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1.
Cardiovasc Digit Health J ; 5(1): 8-14, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38390583

ABSTRACT

Background: The availability of portable and wearable electrocardiographic (ECG) devices has increased secondary to technological development. Single-lead ECG recordings have been shown to reliably detect and characterize cardiac rhythms such as atrial fibrillation. Acquisition of precordial electrodes for full 12-lead ECG reconstruction from bipolar recordings is complicated by the absence of a body ground/Wilson central terminal electrode. The extent of difference between standard precordial leads and those from a wearable bipolar ECG recorder has not been characterized. Objective: The purpose of this study was to characterize the precordial ECG lead set from sequential bipolar recordings from an ECG ring wearable device. Methods: In 70 patients who wore an ECG device on a right-hand finger, sequential precordial leads (CR1-CR6) were obtained along with chest electrodes (V1-V6). During acquisition of the modified precordial lead CR6, a full standardized 12-lead ECG capture was obtained. Signal quality was assessed using automated analysis software, and correlation values between the ring-derived ECG precordial leads and standard ECG leads were compared with regard to QRS duration, QT width, and RR interval. Results: High concordance in the morphologies of precordial ECG leads obtained in a standard fashion and those recorded through an ECG ring was observed. Morphologic alignment improved with increasing laterality of the precordial lead with chest to right arm ring recording (CR5, CR6) compared with anterior chest leads to right arm (CR1, CR2). Segmental measurements of QRS duration and QT segment were well aligned and of high correlation. Conclusion: Wearable ring-based ECG technology is capable of high-fidelity recordings of precordial leads for nonsimultaneous reconstruction of complete ECG sets. These recordings correlate highly with surface-obtained QRS and QT duration measurements and have significant implications for clinical applications. Uninterpretable tracings were primarily due to electrode noise from poor electrode contact.

2.
J Environ Manage ; 324: 116359, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-36206652

ABSTRACT

Historically, relying on plot-level inventories impeded our ability to quantify large-scale change in plant biomass, a key indicator of conservation practice outcomes in rangeland systems. Recent technological advances enable assessment at scales appropriate to inform management by providing spatially comprehensive estimates of productivity that are partitioned by plant functional group across all contiguous US rangelands. We partnered with the Sage Grouse and Lesser Prairie-Chicken Initiatives and the Nebraska Natural Legacy Project to demonstrate the ability of these new datasets to quantify multi-scale changes and heterogeneity in plant biomass following mechanical tree removal, prescribed fire, and prescribed grazing. In Oregon's sagebrush steppe, for example, juniper tree removal resulted in a 21% increase in one pasture's productivity and an 18% decline in another. In Nebraska's Loess Canyons, perennial grass productivity initially declined 80% at sites invaded by trees that were prescriptively burned, but then fully recovered post-fire, representing a 492% increase from nadir. In Kansas' Shortgrass Prairie, plant biomass increased 4-fold (966,809 kg/ha) in pastures that were prescriptively grazed, with gains highly dependent upon precipitation as evidenced by sensitivity of remotely sensed estimates (SD ± 951,308 kg/ha). Our results emphasize that next-generation remote sensing datasets empower land managers to move beyond simplistic control versus treatment study designs to explore nuances in plant biomass in unprecedented ways. The products of new remote sensing technologies also accelerate adaptive management and help communicate wildlife and livestock forage benefits from management to diverse stakeholders.


Subject(s)
Conservation of Natural Resources , Fires , Animals , Conservation of Natural Resources/methods , Ecosystem , Trees , Livestock
3.
Front Pediatr ; 10: 914942, 2022.
Article in English | MEDLINE | ID: mdl-35935364

ABSTRACT

Background: Thyroid gland malignancies are rare in pediatric patients (0.7% of tumors); only 1.8% are observed in patients aged <20 years, with a higher prevalence recorded in women and adolescents. Risk factors include genetic syndromes, MEN disorders, autoimmune diseases, and exposure to ionizing radiation. Radiotherapy is also associated with an increased risk of secondary thyroid cancer. This study describes the clinical features and surgical outcomes of primary and secondary thyroid tumors in pediatric patients. Methods: Institutional data were collected from eight international surgical oncology centers for pediatric patients with thyroid cancer between 2000 and 2020. Statistical analyses were performed using the GraphPad Prism software. Results: Among 255 total cases of thyroid cancer, only 13 (5.1%) were secondary tumors. Primary thyroid malignancies were more likely to be multifocal in origin (odds ratio [OR] 1.993, 95% confidence interval [CI].7466-5.132, p = 0.2323), have bilateral glandular location (OR 2.847, 95% CI.6835-12.68, p = 0.2648), and be metastatic at first diagnosis (OR 1.259, 95% CI.3267-5.696, p > 0.999). Secondary tumors showed a higher incidence of disease relapse (OR 1.556, 95% CI.4579-5.57, p = 0.4525) and surgical complications (OR 2.042, 95% CI 0.7917-5.221, p = 0.1614), including hypoparathyroidism and recurrent laryngeal nerve injury. The overall survival (OS) was 99% at 1 year and 97% after 10 years. No EFS differences were evident between the primary and secondary tumors (chi-square 0.7307, p = 0.39026). Conclusions: This multicenter study demonstrated excellent survival in pediatric thyroid malignancies. Secondary tumors exhibited greater disease relapse (15.8 vs. 10.5%) and a higher incidence of surgical complications (36.8 vs. 22.2%).

4.
Ecol Appl ; 32(1): e02480, 2022 01.
Article in English | MEDLINE | ID: mdl-34674399

ABSTRACT

In this era of global environmental change and rapid regime shifts, managing core areas that species require to survive and persist is a grand challenge for conservation. Wildlife monitoring data are often limited or local in scale. The emerging ability to map and track spatial regimes (i.e., the spatial manifestation of state transitions) using advanced geospatial vegetation data has the potential to provide earlier warnings of habitat loss because many species of conservation concern strongly avoid spatial regime boundaries. Using 23 yr of data for the lek locations of Greater Prairie-Chicken (Tympanuchus cupido; GPC) in a remnant grassland ecosystem, we demonstrate how mapping changes in the boundaries between grassland and woodland spatial regimes provide a spatially explicit early warning signal for habitat loss for an iconic and vulnerable grassland-obligate known to be highly sensitive to woody plant encroachment. We tested whether a newly proposed metric for the quantification of spatial regimes captured well-known responses of GPC to woody plant expansion into grasslands. Resource selection functions showed that the grass:woody spatial regime boundary strength explained the probability of 80% of relative lek occurrence, and GPC strongly avoided grass:woody spatial regime boundaries at broad scales. Both findings are consistent with well-known expectations derived from GPC ecology. These results provide strong evidence for vegetation-derived delineations of spatial regimes to serve as generalized signals of early warning for state transitions that have major consequences to biodiversity conservation. Mapping spatial regime boundaries over time provided interpretable early warnings of habitat loss. Woody plant regimes displaced grassland regimes starting from the edges of the study area and constricting inward. Correspondingly, the relative probability of lek occurrence constricted in space. Similarly, the temporal trajectory of spatial regime boundary strength increased over time and moved closer to the observed limit of GPC lek site usage relative to grass:woody boundary strength. These novel spatial metrics allow managers to rapidly screen for early warning signals of spatial regime shifts and adapt management practices to defend and grow habitat cores at broad scales.


Subject(s)
Ecosystem , Forests , Biodiversity , Conservation of Natural Resources/methods , Grassland , Poaceae , Wood
5.
J Pediatr Surg ; 56(5): 929-932, 2021 May.
Article in English | MEDLINE | ID: mdl-33276972

ABSTRACT

BACKGROUND: To determine if birth-weight (BW) influences primary surgical management of newborns undergoing operation for esophageal atresia and tracheo-esophageal fistula (EA-TEF). METHODS: Newborns undergoing repair of esophageal atresia at a single specialist centre between 1999 and 2017 were categorised into three groups based on BW; Group A < 1.5 kg, Group B <2.5 kg and Group C >2.5 kg. Outcome data analysed were (i) technical ability of the surgeon to perform primary esophageal anastomosis, (ii) anastomotic leak, (iii) anastomotic stricture, (iv) esophageal replacement, (v) need for other procedures notably fundoplication, aortopexy, tracheostomy and (vi) mortality. Statistical analysis was performed using a two-tailed Fisher's exact test and logistic regression. RESULTS: 198 patients underwent surgery for EA-TEF during the study period, Group A (n = 13), Group B (n = 73) and Group C (n = 112). Inability to perform a primary anastomosis was significantly higher in Group A vs Group B (p = 0.003) and Group C (p = 0.004). Birthweight was a significant variable in the ability to perform a primary esophageal anastomosis (OR 1.009, p = 0.004). Mortality rate was significantly higher in Group A vs Group C (P = 0.0158). CONCLUSIONS: Very low birth weight infants are less likely to achieve a definitive primary anastomosis during emergent repair of esophageal atresia, and have a higher mortality.


Subject(s)
Esophageal Atresia , Tracheoesophageal Fistula , Anastomosis, Surgical , Birth Weight , Esophageal Atresia/surgery , Humans , Infant , Infant, Newborn , Postoperative Complications , Retrospective Studies , Tracheoesophageal Fistula/surgery , Treatment Outcome
6.
Bioscience ; 70(1): 90-96, 2020 Jan 01.
Article in English | MEDLINE | ID: mdl-31949318

ABSTRACT

Conservationists are increasingly convinced that coproduction of science enhances its utility in policy, decision-making, and practice. Concomitant is a renewed reliance on privately owned working lands to sustain nature and people. We propose a coupling of these emerging trends as a better recipe for conservation. To illustrate this, we present five elements of coproduction, contrast how they differ from traditional approaches, and describe the role of scientists in successful partnerships. Readers will find coproduction more demanding than the loading dock approach to science delivery but will also find greater rewards, relevance, and impact. Because coproduction is novel and examples of it are rare, we draw on our roles as scientists within the US Department of Agriculture-led Sage Grouse Initiative, North America's largest effort to conserve the sagebrush ecosystem. As coproduction and working lands evolve, traditional approaches will be replaced in order to more holistically meet the needs of nature and people.

7.
Ecol Appl ; 29(3): e01862, 2019 04.
Article in English | MEDLINE | ID: mdl-30706573

ABSTRACT

Rangelands cover 40-50% of the Earth's terrestrial surface. While often characterized by limited, yet variable resource availability, rangelands are vital for humans, providing numerous ecosystem goods and services. In the conterminous United States (CONUS), the dominant component of rangeland conservation is a network of public rangelands, concentrated in the west. Public rangelands are interspersed with private and tribal rangelands resulting in a complex mosaic of land tenure and management priorities. We quantify ownership patterns of rangeland production at multiple scales across CONUS and find that both total production and average productivity of private rangelands is more than twice that of public and tribal rangelands. At finer scales, private rangelands are consistently more productive than their public counterparts. We also demonstrate an inverse relationship between public rangeland acreage and productivity. While conserving acreage is crucial to rangeland conservation, just as critical are broad-scale ecological patterns and processes that sustain ecosystem services. Across CONUS, ownership regimes capture distinct elements of these patterns and services, demonstrated through disparate production dynamics. As ownership determines the range of feasible conservation actions, and the technical and financial resources available to implement them, understanding ownership-production dynamics is critical for effective and sustained conservation of rangeland ecosystem services.


Subject(s)
Ecosystem , Ownership , Conservation of Natural Resources , Ecology , Humans , Software
8.
Nat Ecol Evol ; 2(10): 1531-1540, 2018 10.
Article in English | MEDLINE | ID: mdl-30224814

ABSTRACT

Essential Biodiversity Variables (EBVs) allow observation and reporting of global biodiversity change, but a detailed framework for the empirical derivation of specific EBVs has yet to be developed. Here, we re-examine and refine the previous candidate set of species traits EBVs and show how traits related to phenology, morphology, reproduction, physiology and movement can contribute to EBV operationalization. The selected EBVs express intra-specific trait variation and allow monitoring of how organisms respond to global change. We evaluate the societal relevance of species traits EBVs for policy targets and demonstrate how open, interoperable and machine-readable trait data enable the building of EBV data products. We outline collection methods, meta(data) standardization, reproducible workflows, semantic tools and licence requirements for producing species traits EBVs. An operationalization is critical for assessing progress towards biodiversity conservation and sustainable development goals and has wide implications for data-intensive science in ecology, biogeography, conservation and Earth observation.


Subject(s)
Biodiversity , Conservation of Natural Resources/methods , Invertebrates , Life History Traits , Plants , Vertebrates , Animals
9.
Sci Rep ; 8(1): 2870, 2018 02 12.
Article in English | MEDLINE | ID: mdl-29434266

ABSTRACT

Plant traits are both responsive to local climate and strong predictors of primary productivity. We hypothesized that future climate change might promote a shift in global plant traits resulting in changes in Gross Primary Productivity (GPP). We characterized the relationship between key plant traits, namely Specific Leaf Area (SLA), height, and seed mass, and local climate and primary productivity. We found that by 2070, tropical and arid ecosystems will be more suitable for plants with relatively lower canopy height, SLA and seed mass, while far northern latitudes will favor woody and taller plants than at present. Using a network of tower eddy covariance CO2 flux measurements and the extrapolated plant trait maps, we estimated the global distribution of annual GPP under current and projected future plant community distribution. We predict that annual GPP in northern biomes (≥45 °N) will increase by 31% (+8.1 ± 0.5 Pg C), but this will be offset by a 17.9% GPP decline in the tropics (-11.8 ± 0.84 Pg C). These findings suggest that regional climate changes will affect plant trait distributions, which may in turn affect global productivity patterns.


Subject(s)
Plant Leaves/physiology , Algorithms , Climate Change , Ecosystem , Plant Physiological Phenomena
10.
J Pediatr Surg ; 53(2): 281-282, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29305009

ABSTRACT

AIM OF STUDY: The aim of this study was to evaluate management of children with an anterior midline neck swelling by establishing 1) whether a preoperative ultrasound scan (USS) was appropriately requested, performed and reported; 2) whether there was preoperative infection; 3) whether a Sistrunk procedure was performed; 4) the rate of thyroglossal duct cyst (TGDC) recurrence following simple excision vs. Sistrunk procedure. METHODS: A single centre retrospective study of children who underwent surgery for anterior midline neck swelling between April 2000 and May 2015 at our institution was performed. These were identified using a clinical coding system, and data were collected from electronic medical records, radiology, and histopathology reports. Recurrence rates between simple excision and Sistrunk groups were compared using Chi-square test. MAIN RESULTS: 227 patients were identified (115 male, 112 female). 169 (74%) had a preoperative USS. The presence of a thyroid gland was stated in 79% of USS reports. This increased to 92% when the requesting surgeon had specifically asked about this. 48 (21%) patients underwent simple excision, while 175 (77%) had a Sistrunk procedure. Recurrence was significantly more likely following simple excision than a Sistrunk procedure (29% vs 6.9%; P<0.0001). Of 25 TGDC recurrences, 9 (36%) had an inconclusive or alternative histopathological diagnosis at first operation. CONCLUSION: Preoperative USS should be performed in all patients with an anterior midline neck swelling. Appropriate requesting increases likelihood of a report confirming (or otherwise) the presence of a thyroid gland. A Sistrunk procedure is the operation of choice in all children presenting with an anterior midline neck swelling. The surgeon cannot reliably differentiate a TGDC from alternative pathology intraoperatively. LEVEL OF EVIDENCE: Treatment study: level IV.


Subject(s)
Practice Patterns, Physicians'/statistics & numerical data , Thyroglossal Cyst/diagnostic imaging , Thyroglossal Cyst/surgery , Child , Child, Preschool , Diagnosis, Differential , Female , Humans , Male , Recurrence , Retrospective Studies , Thyroglossal Cyst/complications , Ultrasonography
11.
Rangel Ecol Manag ; 71(6): 659-670, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30800013

ABSTRACT

New concepts have emerged in theoretical ecology with the intent to quantify complexities in ecological change that are unaccounted for in state-and-transition models and to provide applied ecologists with statistical early warning metrics able to predict and prevent state transitions. With its rich history of furthering ecological theory and its robust and broad-scale monitoring frameworks, the rangeland discipline is poised to empirically assess these newly proposed ideas while also serving as early adopters of novel statistical metrics that provide advanced warning of a pending shift to an alternative ecological regime. Were view multivariate early warning and regime shift detection metrics, identify situations where various metrics will be most useful for rangeland science, and then highlight known shortcomings. Our review of a suite of multivariate-based regime shift/early warning indicators provides a broad range of metrics applicable to a wide variety of data types or contexts, from situations where a great deal is known about the key system drivers and a regime shift is hypothesized a priori, to situations where the key drivers and the possibility of a regime shift are both unknown. These metrics can be used to answer ecological state-and-transition questions, inform policymakers, and provide quantitative decision-making tools for managers.

12.
J Pediatr Surg ; 51(9): 1426-8, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27032608

ABSTRACT

AIM OF THE STUDY: To assess the safety and effectiveness of fluoroscopic balloon dilatation (FBD) in children with esophageal anastomotic stricture after surgical repair of esophageal atresia. METHODS: All patients undergoing surgery for esophageal atresia and requiring dilatation(s) during a consecutive 15-year period [April 2000-September 2014] were analyzed. Dilatations were performed as day case procedures under general anesthesia using a radial force generating balloon device (Boston Scientific Corporation) by surgeons. Outcomes assessed included - (1) the number of dilatations/patient, (2) effectiveness and (3) need for surgery and (4) complications. RESULTS: One hundred thirty seven patients underwent 625 FBD sessions (median 3 dilations per patient; range 1-24 dilatations). Median age at 1st FBD was 0.74years (range 0.05-16.1years). Balloon catheter sizes ranged from 6mm to 20mm. FBD yielded excellent results in 99 patients (74%), while 17 cases (13%) had mild ongoing dysphagia/dysmotility. Ten patients (7%) required further dilatation(s) to control symptoms. No patient(s) required esophageal stenting. Five cases required G-tube feeds as a result of oral aversion behavior - all of these cases were complex/VACTERL patients. Only 1 minor radiological leak occurred after a dilatation session and this did not require surgical intervention. A single patient (long gap EA TEF) with severe neurological impairment having multiple dilatations and stricture resection ultimately required esophageal replacement. Anti-reflux surgery was performed in 36 patients (26%) for medical therapy resistant GER. CONCLUSION: FBD for anastomotic stricture(s) following esophageal atresia repair achieved very good outcomes for the majority of EA TEF patients. The procedure can be accomplished safely as indicated by the low complication rate herein reported. Although some children may require more than one dilatation session prompt relief of symptoms can be achieved with a vigilant care program co-ordinated by a multidisciplinary specialist EA TEF team.


Subject(s)
Dilatation/methods , Esophageal Atresia/surgery , Esophageal Stenosis/therapy , Esophagoplasty , Postoperative Complications/therapy , Adolescent , Anastomosis, Surgical , Child , Child, Preschool , Dilatation/instrumentation , Esophageal Stenosis/diagnostic imaging , Esophageal Stenosis/etiology , Esophagus/surgery , Female , Fluoroscopy , Humans , Infant , Infant, Newborn , Male , Postoperative Complications/diagnostic imaging , Treatment Outcome , United Kingdom
13.
J Pediatr Surg ; 51(4): 588-91, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26382287

ABSTRACT

BACKGROUND: Children with empyema are managed at our center using a protocol-driven clinical care pathway. Chemical fibrinolysis is deployed as first-line management for significant pleural disease. We therefore examined clinical outcome(s) to benchmark standards of care while analyzing disease severity with introduction of the pneumococcal conjugate vaccine. METHODS: Medical case-records of children managed at a UK pediatric center were surveyed from Jan 2006 to Dec 2012. Binary logistic regression was utilized to study failure of fibrinolytic therapy. The effects of age, comorbidity, number of days of intravenous antibiotics prior to drainage and whether initial imaging showed evidence of necrotizing disease were also studied. RESULTS: A total of 239 children were treated [age range 4months-19years; median 4years]. A decreasing number of patients presenting year-on-year since 2006 with complicated pleural infections was observed. The majority of children were successfully managed without surgery using antibiotics alone (27%) or a fine-bore chest-drain and urokinase (71%). Only 2% of cases required primary thoracotomy. 14.7% cases failed fibrinolysis and required a second intervention. The only factor predictive of failure and need for surgery was suspicion of necrotizing disease on initial imaging (P=0.002, OR 8.69). CONCLUSION: Pediatric patients with pleural empyema have good outcomes when clinical care is led by a multidisciplinary team and protocol driven care pathway. Using a 'less is best' approach few children require surgery.


Subject(s)
Conservative Treatment/methods , Disease Management , Empyema, Pleural/therapy , Pleural Effusion/therapy , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Logistic Models , Male , Retrospective Studies , Treatment Outcome , Young Adult
14.
J Pediatr Surg ; 50(2): 275-9, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25638618

ABSTRACT

BACKGROUND AND AIMS: Gastrooesophageal reflux disease (GERD) is a significant problem in children with neurological impairment (NI) with high failure rates for fundoplication. Fundoplication with vagotomy and pyloroplasty (FVP) can improve the outcome by altering the sensory or motor dysfunction associated with the reflux. We report our comparative outcomes for simple fundoplication (SF) and FVP in NI children. METHODS: Case records of all patients having fundoplication under a single consultant at a tertiary UK paediatric surgical centre between January 1997 and December 2012 were retrospectively assessed for recurrent symptoms and redo surgery. The data were collected using a Microsoft Excel database and analysed on Graphpad prism software program. Data are median (range). P value<0.05 was considered significant. RESULTS: Data were available for 244 out of 275 patients who underwent fundoplication during this period (157 SF and 87 FVP). Neurological disease or known syndromes were recorded in 158 patients. Thirty-five children had congenital anatomical abnormalities. Laparoscopic fundoplication was done in 37 cases. Revisional surgery for recurrent symptoms was performed in 22 patients. In the neurologically normal children, all of whom had SF, the revision rate was 6.5%. In the NI children the revision rates were 18.5% for SF and 3.9% for FVP, respectively (Fisher's exact, P<0.05). The median time to redo surgery was 10 (1-63) months, and the median time to follow up was 19.5 (2-177) months. CONCLUSIONS: There appears to be a significantly lower need for redo surgery following FVP than SF in children with NI.


Subject(s)
Fundoplication/methods , Gastroesophageal Reflux/complications , Gastroesophageal Reflux/surgery , Nervous System Diseases/complications , Plastic Surgery Procedures/methods , Pylorus/surgery , Vagotomy, Truncal/methods , Child , Female , Follow-Up Studies , Humans , Laparoscopy , Male , Reoperation , Retrospective Studies , Time Factors
15.
Int J Biometeorol ; 58(6): 1305-15, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24005849

ABSTRACT

The land surface phenology (LSP) start of season (SOS) metric signals the seasonal onset of vegetation activity, including canopy growth and associated increases in land-atmosphere water, energy and carbon (CO2) exchanges influencing weather and climate variability. The vegetation optical depth (VOD) parameter determined from satellite passive microwave remote sensing provides for global LSP monitoring that is sensitive to changes in vegetation canopy water content and biomass, and insensitive to atmosphere and solar illumination constraints. Direct field measures of canopy water content and biomass changes desired for LSP validation are generally lacking due to the prohibitive costs of maintaining regional monitoring networks. Alternatively, a normalized microwave reflectance index (NMRI) derived from GPS base station measurements is sensitive to daily vegetation water content changes and may provide for effective microwave LSP validation. We compared multiyear (2007-2011) NMRI and satellite VOD records at over 300 GPS sites in North America, and their derived SOS metrics for a subset of 24 homogenous land cover sites to investigate VOD and NMRI correspondence, and potential NMRI utility for LSP validation. Significant correlations (P<0.05) were found at 276 of 305 sites (90.5 %), with generally favorable correspondence in the resulting SOS metrics (r (2)=0.73, P<0.001, RMSE=36.8 days). This study is the first attempt to compare satellite microwave LSP metrics to a GPS network derived reflectance index and highlights both the utility and limitations of the NMRI data for LSP validation, including spatial scale discrepancies between local NMRI measurements and relatively coarse satellite VOD retrievals.


Subject(s)
Geographic Information Systems , Microwaves , Plant Development , Satellite Imagery , Biomass , Seasons , Water
16.
Glob Chang Biol ; 19(10): 3111-22, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23749682

ABSTRACT

The rate of vegetation recovery from boreal wildfire influences terrestrial carbon cycle processes and climate feedbacks by affecting the surface energy budget and land-atmosphere carbon exchange. Previous forest recovery assessments using satellite optical-infrared normalized difference vegetation index (NDVI) and tower CO(2) eddy covariance techniques indicate rapid vegetation recovery within 5-10 years, but these techniques are not directly sensitive to changes in vegetation biomass. Alternatively, the vegetation optical depth (VOD) parameter from satellite passive microwave remote sensing can detect changes in canopy biomass structure and may provide a useful metric of post-fire vegetation response to inform regional recovery assessments. We analyzed a multi-year (2003-2010) satellite VOD record from the NASA AMSR-E (Advanced Microwave Scanning Radiometer for EOS) sensor to estimate forest recovery trajectories for 14 large boreal fires from 2004 in Alaska and Canada. The VOD record indicated initial post-fire canopy biomass recovery within 3-7 years, lagging NDVI recovery by 1-5 years. The VOD lag was attributed to slower non-photosynthetic (woody) and photosynthetic (foliar) canopy biomass recovery, relative to the faster canopy greenness response indicated from the NDVI. The duration of VOD recovery to pre-burn conditions was also directly proportional (P < 0.01) to satellite (moderate resolution imaging spectroradiometer) estimated tree cover loss used as a metric of fire severity. Our results indicate that vegetation biomass recovery from boreal fire disturbance is generally slower than reported from previous assessments based solely on satellite optical-infrared remote sensing, while the VOD parameter enables more comprehensive assessments of boreal forest recovery.


Subject(s)
Biomass , Fires , Trees/growth & development , Alaska , Microwaves , Remote Sensing Technology , Satellite Communications , Yukon Territory
17.
Biochem J ; 449(3): 729-40, 2013 Feb 01.
Article in English | MEDLINE | ID: mdl-23126257

ABSTRACT

The electron transfer molecules plastoquinone and ubiquinone are formed by the condensation of aromatic head groups with long-chain prenyl diphosphates. In the present paper we report the cloning and characterization of two genes from tomato (Solanum lycopersicum) responsible for the production of solanesyl and decaprenyl diphosphates. SlSPS (S. lycopersicum solanesyl diphosphate synthase) is targeted to the plastid and both solanesol and plastoquinone are associated with thylakoid membranes. A second gene [SlDPS (S. lycopersicum solanesyl decaprenyl diphosphate synthase)], encodes a long-chain prenyl diphosphate synthase with a different subcellular localization from SlSPS and can utilize geranyl, farnesyl or geranylgeranyl diphosphates in the synthesis of C45 and C50 prenyl diphosphates. When expressed in Escherichia coli, SlSPS and SlDPS extend the prenyl chain length of the endogenous ubiquinone to nine and ten isoprene units respectively. In planta, constitutive overexpression of SlSPS elevated the plastoquinone content of immature tobacco leaves. Virus-induced gene silencing showed that SlSPS is necessary for normal chloroplast structure and function. Plants silenced for SlSPS were photobleached and accumulated phytoene, whereas silencing SlDPS did not affect leaf appearance, but impacted on primary metabolism. The two genes were not able to complement silencing of each other. These findings indicate a requirement for two long-chain prenyl diphosphate synthases in the tomato.


Subject(s)
Alkyl and Aryl Transferases/metabolism , Plant Proteins/metabolism , Solanum lycopersicum/enzymology , Alkyl and Aryl Transferases/antagonists & inhibitors , Alkyl and Aryl Transferases/genetics , Amino Acid Sequence , Cloning, Molecular , DNA, Plant/genetics , Gene Silencing , Genes, Plant , Solanum lycopersicum/genetics , Molecular Sequence Data , Phylogeny , Plant Proteins/genetics , Plastoquinone/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Substrate Specificity , Terpenes/metabolism
18.
J Pediatr Surg ; 47(6): 1118-22, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22703780

ABSTRACT

PURPOSE: The relationship between congenital abdominal wall defects (AWDs) and undescended testes (UDTs) is poorly defined. We report a study of infants with AWD and UDT. METHODS: Hospital records of newborns with AWD managed during 1998 to 2008 were reviewed. Data analyzed included nature of AWD, position of the testes at birth, final position of the testes, and surgical management. RESULTS: A total of 218 newborns with AWD were identified; 106 (49%) were boys. Of 79 boys with gastroschisis, 26 (33%) had UDT involving 35 testes. Of 27 with exomphalos, 6 (22%) had UDT involving 11 testes. Prolapsed testes were placed in the abdomen at AWD repair, whereas others were observed for "spontaneous" descent. Of 35 UDT in gastroschisis infants, 18 descended spontaneously, and 10 required orchidopexy. Three boys underwent laparoscopy for impalpable testes, 2 underwent orchidectomy, and 1 had bilaterally absent testes. Three cases await orchidopexy. In exomphalos boys with 11 UDTs, 1 gonad descended spontaneously, and 6 had groin exploration (1 absent testis and 5 orchidopexies). Two boys await orchidopexy, and 1 boy (bilateral impalpable testes) was lost to follow-up. CONCLUSION: Abdominal wall defects are strongly associated with UDT. In boys with gastroschisis, spontaneous descent of the testes may be anticipated in 50% of cases. In those with exomphalos, orchidopexy should be scheduled.


Subject(s)
Abdominal Wall/abnormalities , Abnormalities, Multiple/epidemiology , Cryptorchidism/epidemiology , Abdominal Wall/surgery , Abnormalities, Multiple/surgery , Comorbidity , Cryptorchidism/surgery , Gastroschisis/epidemiology , Gastroschisis/surgery , Hernia, Umbilical/epidemiology , Hernia, Umbilical/surgery , Humans , Infant, Newborn , Laparoscopy/statistics & numerical data , Male , Orchiectomy/statistics & numerical data , Orchiopexy/statistics & numerical data , Palpation , Remission, Spontaneous , Retrospective Studies , Testis/abnormalities , Time Factors
19.
Phytochemistry ; 79: 78-86, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22595361

ABSTRACT

Targeting Induced Local Lesions IN Genomes (TILLING) combines chemical mutagenesis with high throughput screening to allow the generation of alleles of selected genes. In this study, TILLING has been applied to produce a series of mutations in genes encoding essential components of the tomato light signal transduction pathway in an attempt to enhance fruit nutritional quality. Point mutations to DEETIOLATED1 (DET1), which is responsible for the high pigment2 (hp2) tomato mutant, resulted in elevated levels of both carotenoid and phenylpropanoid phytonutrients in ripe fruit, whilst immature fruit showed increased chlorophyll content, photosynthetic capacity and altered fruit morphology. Furthermore, genotypes with mutations to the UV-DAMAGED DNA BINDING PROTEIN 1 (DDB1), COP1 and COP1like were also characterised. These genotypes largely did not display phenotypes characteristic of mutation to light signalling components but their characterisation has enabled interrogation of structure function relationships of the mutated genes.


Subject(s)
Alleles , Genes, Plant/genetics , Genomics , High-Throughput Screening Assays/methods , Light , Mutagenesis/drug effects , Signal Transduction/genetics , Signal Transduction/radiation effects , Solanum lycopersicum/genetics , Carotenoids/metabolism , Chlorophyll/metabolism , Ethyl Methanesulfonate/pharmacology , Fruit/genetics , Fruit/growth & development , Fruit/radiation effects , Solanum lycopersicum/cytology , Solanum lycopersicum/metabolism , Solanum lycopersicum/radiation effects , Phenols/metabolism , Photosynthesis/genetics , Photosynthesis/radiation effects , Point Mutation , Principal Component Analysis
20.
Plant Physiol ; 153(4): 1619-29, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20566708

ABSTRACT

Anthocyanins are important health-promoting phytochemicals that are abundant in many fleshy fruits. Bilberry (Vaccinium myrtillus) is one of the best sources of these compounds. Here, we report on the expression pattern and functional analysis of a SQUAMOSA-class MADS box transcription factor, VmTDR4, associated with anthocyanin biosynthesis in bilberry. Levels of VmTDR4 expression were spatially and temporally linked with color development and anthocyanin-related gene expression. Virus-induced gene silencing was used to suppress VmTDR4 expression in bilberry, resulting in substantial reduction in anthocyanin levels in fully ripe fruits. Chalcone synthase was used as a positive control in the virus-induced gene silencing experiments. Additionally, in sectors of fruit tissue in which the expression of the VmTDR4 gene was silenced, the expression of R2R3 MYB family transcription factors related to the biosynthesis of flavonoids was also altered. We conclude that VmTDR4 plays an important role in the accumulation of anthocyanins during normal ripening in bilberry, probably through direct or indirect control of transcription factors belonging to the R2R3 MYB family.


Subject(s)
Anthocyanins/biosynthesis , Fruit/metabolism , Plant Proteins/metabolism , Transcription Factors/metabolism , Vaccinium myrtillus/metabolism , Cloning, Molecular , Flavonoids/biosynthesis , Fruit/genetics , Gene Expression Regulation, Plant , Gene Silencing , MADS Domain Proteins/genetics , MADS Domain Proteins/metabolism , Phylogeny , Plant Proteins/genetics , RNA, Plant/genetics , Transcription Factors/genetics , Vaccinium myrtillus/genetics
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