Evidence for heterothermic endothermy and reptile-like eggshell mineralization in Troodon, a non-avian maniraptoran theropod.

The dinosaur-bird transition involved several anatomical, biomechanical, and physiological modifications of the theropod bauplan. Non-avian maniraptoran theropods, such as Troodon, are key to better understand changes in thermophysiology and reproduction occurring during this transition. Here, we applied dual clumped isotope (Δ47 and Δ48) thermometry, a technique that resolves mineralization temperature and other nonthermal information recorded in carbonates, to eggshells from Troodon, modern reptiles, and modern birds. Troodon eggshells show variable temperatures, namely 42 and 29 ± 2 °C, supporting the hypothesis of an endothermic thermophysiology with a heterothermic strategy for this extinct taxon. Dual clumped isotope data also reveal physiological differences in the reproductive systems between Troodon, reptiles, and birds. Troodon and modern reptiles mineralize their eggshells indistinguishable from dual clumped isotope equilibrium, while birds precipitate eggshells characterized by a positive disequilibrium offset in Δ48. Analyses of inorganic calcites suggest that the observed disequilibrium pattern in birds is linked to an amorphous calcium carbonate (ACC) precursor, a carbonate phase known to accelerate eggshell formation in birds. Lack of disequilibrium patterns in reptile and Troodon eggshells implies these vertebrates had not acquired the fast, ACC-based eggshell calcification process characteristic of birds. Observation that Troodon retained a slow reptile-like calcification suggests that it possessed two functional ovaries and was limited in the number of eggs it could produce; thus its large clutches would have been laid by several females. Dual clumped isotope analysis of eggshells of extinct vertebrates sheds light on physiological information otherwise inaccessible in the fossil record.

Exploratory factor and confirmatory analyses of the polycystic ovary syndrome health-related quality of life questionnaire (PCOSQ-50).

BACKGROUND: A condition-specific instrument is necessary to measure the health-related quality of life among those with polycystic ovary syndrome (PCOS), the most common chronic endocrinopathy among women. The first instrument was developed in 1988, followed by several revisions. However, further recommendations from all versions include additional application and measurement among different cultural populations of women with PCOS and psychometric testing based on use among larger samples of women with PCOS. Thus, the purpose of this study was to explore the factor structure of the Polycystic Ovary Syndrome Questionnaire (PCOSQ-50) using an international cross-sectional survey data from women with PCOS aged 18-42 years. METHODS: Using data from the largest known international cross-sectional study of women with PCOS aged 18-42 years (n = 935) to date, exploratory factor and confirmatory analyses were conducted for the PCOSQ-50, followed by factor labeling using a thematic analysis approach. RESULTS: Respondents were 31.0 ± 5.8 years of age, mostly White (72%), well-educated (56% had a college degree), married (69%), and employed full-time (65%). Three-quarters (74%) of the sample had one or more chronic conditions in addition to PCOS. Approximately 20% of the respondents originated from countries such as the United Kingdom, Australia, South Africa, etc. The PCOSQ-50 demonstrated good reliability but may be best described using a 7-factor model. The 7-factor model revealed goodness-of-fit. Thematic analysis suggested the following labels of those seven factors: hirsutism, fertility, isolation/trepidation, sexual function, self-esteem, emotional, and obesity. CONCLUSION: More research is needed to adapt the current PCOSQ-50, as well as to create an age-appropriate PCOS-specific HRQoL instrument for peri-postmenopausal women with PCOS.

Peering down the sink: A review of isoprene metabolism by bacteria.

Isoprene (2-methyl-1,3-butadiene) is emitted to the atmosphere each year in sufficient quantities to rival methane (>500 Tg C yr-1 ), primarily due to emission by trees and other plants. Chemical reactions of isoprene with other atmospheric compounds, such as hydroxyl radicals and inorganic nitrogen species (NOx ), have implications for global warming and local air quality, respectively. For many years, it has been estimated that soil-dwelling bacteria consume a significant amount of isoprene (~20 Tg C yr-1 ), but the mechanisms underlying the biological sink for isoprene have been poorly understood. Studies have indicated or confirmed the ability of diverse bacterial genera to degrade isoprene, whether by the canonical iso-type isoprene degradation pathway or through other less well-characterized mechanisms. Here, we review current knowledge of isoprene metabolism and highlight key areas for further research. In particular, examples of isoprene-degraders that do not utilize the isoprene monooxygenase have been identified in recent years. This has fascinating implications both for the mechanism of isoprene uptake by bacteria, and also for the ecology of isoprene-degraders in the environments.

Analysis of Essential Isoprene Metabolic Pathway Proteins in Variovorax sp. Strain WS11.

Isoprene monooxygenase (IsoMO, encoded by isoABCDEF) initiates the oxidation of the climate-active gas isoprene, with the genes isoGHIJ and aldH nearly always found adjacent to isoABCDEF in extant and metagenome-derived isoprene degraders. The roles of isoGHIJ and aldH are uncertain, although each is essential to isoprene degradation. We report here the characterization of these proteins from two model isoprene degraders, Rhodococcus sp. strain AD45 and Variovorax sp. strain WS11. The genes isoHIJ and aldH from Variovorax and aldH from Rhodococcus were expressed individually in Escherichia coli as maltose binding protein fusions to overcome issues of insolubility. The activity of two glutathione S-transferases from Variovorax, IsoI and IsoJ was assessed with model substrates, and the conversion of epoxyisoprene to the intermediate 1-hydroxy-2-glutathionyl-2-methyl-3-butene (HGMB) was demonstrated. The next step of the isoprene metabolic pathway of Variovorax is catalyzed by the dehydrogenase IsoH, resulting in the conversion of HGMB to 2-glutathionyl-2-methyl-3-butenoic acid (GMBA). The aldehyde dehydrogenases (AldH) from Variovorax and Rhodococcus were examined with a variety of aldehydes, with both exhibiting maximum activity with butanal. AldH significantly increased the rate of production of NADH when added to the IsoH-catalyzed conversion of HGMB to GMBA (via GMB), suggesting a synergistic role for AldH in the isoprene metabolic pathway. An in silico analysis of IsoG revealed that this protein, which is essential for isoprene metabolism in Variovorax, is an enzyme of the formyl CoA-transferase family and is predicted to catalyze the formation of a GMBA-CoA thioester as an intermediate in the isoprene oxidation pathway. IMPORTANCE Isoprene is a climate-active gas, largely produced by trees, which is released from the biosphere in amounts equivalent to those of methane and all other volatile organic compounds combined. Bacteria found in many environments, including soils and on the surface of leaves of isoprene-producing trees, can grow on isoprene and thus may represent a significant biological sink for this globally significant volatile compound and remove isoprene before it escapes to the atmosphere, thus reducing its potency as a climate-active gas. The initial oxidation of isoprene by bacteria is mediated by isoprene monooxygenase encoded by the genes isoABCDEF. In isoprene-degrading bacteria, a second gene cluster, isoGHIJ, is also present, although the exact role in isoprene degradation by the proteins encoded by these genes is uncertain. This investigation sheds new light on the roles of these proteins in the isoprene oxidation pathway in two model isoprene-degrading bacteria of the genera Rhodococcus and Variovorax.

Hepatitis B immunity among undergraduate nursing students: A brief report.

BACKGROUND: Health sciences students who report low/equivocal hepatitis B titers may be required to repeat the immunization series, even though the result may not indicate non-immunity. METHOD: To describe hepatitis B immunity patterns, this retrospective, descriptive study utilized de-identified vaccination records and anti-HBs titers of three cohorts of sophomore nursing students entering clinical rotations in 2018-2019. RESULTS: Only 33% of students had initial anti-HBs quantitative serum titer ≥10 mIU/ml, demonstrating immunity. After students with low/equivocal titers (n = 191, 64%) were re-immunized per institution protocol, only 2% (n = 7) were identified as non-responders. Cumulative costs incurred by students for revaccination and repeat titer exceeded $20,000, with a process time of up to 8 months. CONCLUSION: While rates of exposure to hepatitis B in acute care settings have steadily declined in the United States, students who go on to practice in community and public health settings have increased risk of exposure. Following best practices in demonstrating hepatitis B immunity, which include a single challenge dose followed by titer 4 weeks later, would decrease per student costs, wait time, and administrative burden associated with documentation and student counseling.

Next generation nurse scientists: A systems approach to engaging undergraduate students in research.

BACKGROUND: Nursing Doctor of Philosophy program enrollment has declined. Undergraduate nursing student (UGS) research engagement is associated with future graduate education, an essential element for building the nursing faculty pipeline. PURPOSE: (a) To describe the infrastructure and culture-enhancing resources and strategies associated with building UGS research engagement and (b) to evaluate UGS research engagement. METHODS: Guided by a socioecological systems model university and college documents, databases, and college of nursing survey results were used to identify approaches to, and outcomes of, engaging UGS in research. Descriptive statistics were calculated to illustrate 5-year UGS research engagement trends. FINDINGS: Resources and strategies included grant funding, research assistant funding, student research showcases, and faculty mentorship. UGS research 5-year engagement trends included (a) a 75% increase in the number of students mentored, (b) a 30% rise in funded research proposals, and (c) a 54% increase in paid research assistantships. DISCUSSION: Purposefully using existing resources, growing the college of nursing infrastructure, and cultivating a culture recognizing faculty contributions were approaches associated with increased UGS research engagement.

'Omics-guided prediction of the pathway for metabolism of isoprene by Variovorax sp. WS11.

Bacteria that inhabit soils and the leaves of trees partially mitigate the release of the abundant volatile organic compound, isoprene (2-methyl-1,3-butadiene). While the initial steps of isoprene metabolism were identified in Rhodococcus sp. AD45 two decades ago, the isoprene metabolic pathway still remains largely undefined. Limited understanding of the functions of isoG, isoJ and aldH and uncertainty in the route of isoprene-derived carbon into central metabolism have hindered our understanding of isoprene metabolism. These previously uncharacterised iso genes are essential in Variovorax sp. WS11, determined by targeted mutagenesis. Using combined 'omics-based approaches, we propose the complete isoprene metabolic pathway. Isoprene is converted to propionyl-CoA, which is assimilated by the chromosomally encoded methylmalonyl-CoA pathway, requiring biotin and vitamin B12, with the plasmid-encoded methylcitrate pathway potentially providing robustness against limitations in these vitamins. Key components of this pathway were induced by both isoprene and its initial oxidation product, epoxyisoprene, the principal inducer of isoprene metabolism in both Variovorax sp. WS11 and Rhodococcus sp. AD45. Analysis of the genomes of distinct isoprene-degrading bacteria indicated that all of the genetic components of the methylcitrate and methylmalonyl-CoA pathways are not always present in isoprene degraders, although incorporation of isoprene-derived carbon via propionyl-CoA and acetyl-CoA is universally indicated.

Poplar phyllosphere harbors disparate isoprene-degrading bacteria.

The climate-active gas isoprene (2-methyl-1,3-butadiene) is released to the atmosphere in huge quantities, almost equaling that of methane, yet we know little about the biological cycling of isoprene in the environment. Although bacteria capable of growth on isoprene as the sole source of carbon and energy have previously been isolated from soils and sediments, no microbiological studies have targeted the major source of isoprene and examined the phyllosphere of isoprene-emitting trees for the presence of degraders of this abundant carbon source. Here, we identified isoprene-degrading bacteria in poplar tree-derived microcosms by DNA stable isotope probing. The genomes of isoprene-degrading taxa were reconstructed, putative isoprene metabolic genes were identified, and isoprene-related gene transcription was analyzed by shotgun metagenomics and metatranscriptomics. Gram-positive bacteria of the genus Rhodococcus proved to be the dominant isoprene degraders, as previously found in soil. However, a wider diversity of isoprene utilizers was also revealed, notably Variovorax, a genus not previously associated with this trait. This finding was confirmed by expression of the isoprene monooxygenase from Variovorax in a heterologous host. A Variovorax strain that could grow on isoprene as the sole carbon and energy source was isolated. Analysis of its genome confirmed that it contained isoprene metabolic genes with an identical layout and high similarity to those identified by DNA-stable isotope probing and metagenomics. This study provides evidence of a wide diversity of isoprene-degrading bacteria in the isoprene-emitting tree phyllosphere and greatly enhances our understanding of the biodegradation of this important metabolite and climate-active gas.

The Experience of Chemotherapy Teaching and Readability of Chemotherapy Educational Materials for Women with Breast Cancer.

Chemotherapy is one of the most common forms of treatment for women with breast cancer. While chemotherapy is often effective, managing side effects can be challenging. Chemotherapy education is critical in assisting patients to manage side effects and to improve the treatment experience. However, materials are often not thoroughly assessed for readability and format which could be problematic for patients learning self-care while in treatment. We used a mixed-method design to illuminate chemotherapy teaching and focused on readability and format of education materials. We scored the materials using three readability assessments: (1) Flesch Reading Ease (FRE), (2) Flesch-Kincaid (F-K), and (3) a Simple Measure of Gobbledygook (SMOG). We evaluated the format of the materials using Suitability Assessment of Materials (SAM) guidelines. Lastly, we used thematic analysis to describe the experience of 37 women with breast cancer undergoing chemotherapy education. The mean readability of the materials ranged from "difficult" to "fairly difficult" based on the FRE scoring, and the material was written on a 9th- to 13th-grade reading level. Most of the materials scored as "adequate" using SAM guidelines but lacked incorporation of graphics or illustrations. The thematic analysis revealed three major findings: (1) finding control in learning, (2) receiving unexpected support, and (3) learning in unforeseen ways. Nurses need to supplement chemotherapy education materials with individualized teaching to ensure comprehension. Additionally, nurses and website developers may want to consider implementing culturally appropriate information and use videos to combat challenging readability.

Protective effects of Helicobacter pylori membrane vesicles against stress and antimicrobial agents.

Outer-membrane vesicles (OMVs) produced by Helicobacter pylori deliver bacterial components to host cells, provide a mechanism for stabilization of secreted components and may allow the bacteria to exert 'long-range' effects in the gastric niche, promoting persistence. In addition to their well-characterized host cell interactions, membrane vesicles improve stress survival in other bacterial species, and are constitutively produced by both pathogenic and non-pathogenic bacteria. We aimed to determine whether OMVs could improve H. pylori survival of a range of stressors. The effects of purified OMVs on the resistance of H. pylori to a range of environmental and antimicrobial stresses were determined using growth curves and survival assays. Addition of purified OMVs to H. pylori cultures provided dose-dependent protection against hydrogen peroxide-mediated killing. Supplementation with OMVs also partially protected H. pylori against the bactericidal effects of the antibiotics clarithromycin and levofloxacin, but not against amoxicillin nor metronidazole. Addition of purified OMVs allowed H. pylori to grow in the presence of inhibitory concentrations of the antimicrobial peptide LL-37. In the presence of 50 µg OMVs ml-1, significantly enhanced H. pylori growth was observed at higher LL-37 concentrations compared with lower LL-37 concentrations, suggesting that OMV-LL-37 interactions might facilitate release of growth-promoting nutrients. Taken together, these data indicate that production of membrane vesicles could help H. pylori to survive exposure to antibiotics and host antimicrobial defences during infection.

Dithered depth imaging.

Single-photon lidar (SPL) is a promising technology for depth measurement at long range or from weak reflectors because of the sensitivity to extremely low light levels. However, constraints on the timing resolution of existing arrays of single-photon avalanche diode (SPAD) detectors limit the precision of resulting depth estimates. In this work, we describe an implementation of subtractively-dithered SPL that can recover high-resolution depth estimates despite the coarse resolution of the detector. Subtractively-dithered measurement is achieved by adding programmable delays into the photon timing circuitry that introduce relative time shifts between the illumination and detection that are shorter than the time bin duration. Careful modeling of the temporal instrument response function leads to an estimator that outperforms the sample mean and results in depth estimates with up to 13 times lower root mean-squared error than if dither were not used. The simple implementation and estimation suggest that globally dithered SPAD arrays could be used for high spatial- and temporal-resolution depth sensing.

Social construction of biopsychosocial and medical experiences of women with polycystic ovary syndrome.

AIM: To explore the perceived biopsychosocial and medical experiences of women with polycystic ovary syndrome, as presented in stories written by women on a social support website. DESIGN: Qualitative descriptive using low inference content analysis, guided by the social construction of illness theoretical framework. METHODS: In July 2018, 95 of 379 website stories were randomly selected. The stories were analysed, ending in September 2018. RESULTS: Three major themes aligning with framework constructs were identified: Biopsychosocial struggles and management: "I can't even look in the mirror without wanting to cry," Sociocultural navigation: "I feel all alone and no one understands me." and Healthcare encounters: "I don't feel like I'm getting the help I need". These themes revealed that Polycystic ovary syndrome (PCOS) has biological and experiential components, which exist independently of each other and hold social and cultural meanings. CONCLUSION: Care for women with PCOS should be multidisciplinary, multidimensional, and multi-level to ameliorate biopsychosocial issues. Provider (physicians, nurse practitioners, physician assistants) education about PCOS is necessary to enhance timely diagnosis and implement individualized treatment strategies. Non-advanced practice nurses are in a unique position to have an impact on patient satisfaction and clinical outcomes by providing and reinforcing patient education, coordinating management processes, counselling via telephone or in-person appointments and facilitating referrals to ancillary providers. Evidence-based and accessible psychosocial supports and interventions will lead to improved self-esteem and effective coping skills, and reduced stigma-related stress. Lastly, policy changes are warranted to address access to care, health insurance inequities and inadequate funding for PCOS-related research. IMPACT: Increased awareness of PCOS and its biopsychosocial aspects will aid providers with timely diagnosis and meaningful treatment plans. Women with PCOS will gain acknowledgment, acceptance, and insight towards health care and self-management.

Simulation-Based Interprofessional Education in a Rural Setting: The Development and Evaluation of a "Remote-In" Telehealth Scenario.

Simulation-based interprofessional education (IPE) is challenging to implement, especially on rural campuses. This article describes an innovative approach to IPE implementation using telehealth technology. Twenty-nine interdisciplinary students (nursing, pharmacy, and medical) participated in a simulation-based IPE scenario using a telehealth robot. Student experiences were evaluated using a mixed-methods approach. Surveys and video-recorded debriefing sessions revealed the majority of students felt the experience was superior to their previous IPE experiences, facilitated better understanding of disciplinary roles, and provided experience using telehealth tools. Programs considering this approach should have strong community partnerships, institutional support, and shared vision among key stakeholders.

Factors influencing chemotherapy knowledge in women with breast cancer.

BACKGROUND: Chemotherapy knowledge is linked to managing side effects, reducing exposure to potential infection, and adjusting lifestyle behaviors while going through treatment. However, no research exists regarding the influence of patients' personal attributes on chemotherapy knowledge. Aim The aim of this study was to describe the relationships of health literacy and demographics on chemotherapy knowledge among women with breast cancer undergoing treatment. METHOD: We used a descriptive, exploratory design with convenience sampling of women with breast cancer receiving intravenous chemotherapy who completed one mandatory education session. Participants completed a demographic questionnaire and three instruments: 1) Rapid Estimate of Adult Literacy - Short Form (REALM-SF); 2) Shortened Test of Functional Health Literacy in Adults (S-TOFHLA); and 3) Leuven Questionnaire on Patient Knowledge of Chemotherapy (L-PaKC). We used univariate linear regression and ANOVA to identify how health literacy and demographics influenced chemotherapy knowledge. RESULTS: The REALM-SF (p = .022) and S-TOFHLA (p = .023) scores were significantly associated with chemotherapy knowledge. Chemotherapy knowledge scores were affected by marital status (p = .018) and income (p < .001) where married women had significantly higher chemotherapy knowledge scores (M = 92.6, SD = 6.6) than women who were divorced (M = 83.3, SD = 16.7) with a knowledge score difference of -9.3 between the groups (p = .02). Comparisons showed significant differences of chemotherapy knowledge between women with differing income levels. CONCLUSIONS: This study highlights the relevance of considering patients' health literacy and personal attributes such as marital status and income when teaching about chemotherapy.

What makes a good health 'app'? Identifying the strengths and limitations of existing mobile application evaluation tools.

Research using mHealth apps has the potential to positively impact health care management and outcomes. However, choosing an appropriate mHealth app may be challenging for the health researcher. The author team used existing evaluation tools, checklists, and guidelines to assess selected mHealth apps to identify strengths, challenges, and potential gaps within existing evaluation tools. They identified specific evaluation tool components, questions, and items most effective in examining app content, usability, and features, including literacy demand and cultural appropriateness; technical information; practical aspects of app functionality; and evolving capabilities of mobile medical apps. Challenges included the subjective nature of the results, time required to complete the evaluation, lack of emphasis on evidence-based content, and inadequate tool flexibility. Health researchers considering the integration of mobile apps into research will benefit from evaluation tools that assess both evidence-based content and the ability of the mobile app to securely integrate with other digital technologies involved in patient care. Next steps will include the involvement of health care providers and professionals, including nurses a wide range of expertise, to develop an mHealth evaluation tool that focuses on identifying quality, evidence-based mobile apps into patient outcomes research.

Development and Evaluation of a Theory-Based Approach to Reducing Carbon Monoxide (CO) Morbidity and Mortality: The CO Blitz Model.

Carbon monoxide (CO) poisoning is preventable yet remains the most common cause of U.S. non-drug poisoning. The purpose of this non-experimental study was to develop and evaluate the theory-based CO Blitz Model. Events targeted five SC communities; volunteers provided education while local firefighters installed CO alarms. At the 4-6-month follow-up evaluation, all homes still had a functioning CO alarm; most recipients could name CO sources in their homes (78%) and what to do if the alarm sounded (90%). The theory-driven process evaluation revealed the CO Blitz Model was tailorable and effective in addressing unique community resources and needs.

Exploring the Experiential Journey of Women with PCOS Across the Lifespan: A Qualitative Inquiry.

Introduction: Peri-postmenopausal women with the chronic condition polycystic ovary syndrome (PCOS) remain at cardiometabolic risk and/or subsist with established comorbidity while continuing to manage persistent PCOS signs and symptoms, such as hirsutism. Thus, PCOS transcends the reproductive years, yet there is sparse scientific literature on the peri-postmenopausal years of women with PCOS. Purpose: To explore how peri-postmenopausal women's perceptions about PCOS have changed over the lifespan since their PCOS diagnosis. Methods: A cross-sectional survey with one qualitative question was conducted via Research Electronic Data Capture (REDCap) among women with PCOS aged ≥43 years, who were all recruited from PCOS-specific Facebook pages. Of the 107 women completing the survey, 72 substantively answered the qualitative question. The qualitative responses were analyzed using the steps of reflexive thematic analysis. Themes were interpreted and discussed through the lens of the bioecological conceptual model. Results: Respondents were 47.6 (±4.1) years of age, primarily White (87.5%), employed full time (65.3%), and married (75%) with children (68%). Four overall themes were identified: 1) dismissal 2) information desert, 3) PCOS experience over the lifespan, and 4) mindset. Conclusion: The study findings illustrated the unique healthcare needs among peri-postmenopausal women with PCOS. Further research is needed to further explore their healthcare concerns and psychosocial needs followed by studies that develop and assess interventions that promote symptom and adaptive coping strategies across their lifespan.

"We rely on each other": A qualitative exploration of rural Eastern Region Native American experiences during the COVID-19 pandemic.

Background: Native American communities suffered disproportionately negative effects during the COVID-19 pandemic, yet no research has explored the experiences of rural Eastern Region Native Americans. Methods: Informed by the Native Reliance Model and Indigenous Standpoint Theory, we conducted a qualitative descriptive project in the Spring and Summer of 2022; data included semi-structured interviews and focus groups with 24 individuals representing five South Carolina tribal groups. Findings: Thematic analysis yielded four emergent themes: 1) "Let's just finish the Indians off": Pandemic distrust rooted in historical and contemporary Native American experiences; 2) "We have been misled": Making sense of conflicting public health information; 3) "I'm not giving it to some innocent person": COVID-19 mitigation behaviors as Native American cultural practice; and 4) "We put the plan in place": Self-advocacy and action as a source of Native American pride and responsibility. Interpretation: These participants demonstrated resiliency grounded in family and tribal ties, even in the face of personal losses, economic struggles, and healthcare barriers. To strike a balance between cultural traditions and public health recommendations, public health practitioners should 1) build partnerships with community leaders, elders, and tribal health authorities to facilitate the development of culturally respectful interventions that address specific health concerns in the context of historical traumas; and 2) implement alternative methods of communication and engagement to ensure equitable access to healthcare services in rural locations, such as collaborating with community organizations, deploying mobile health units, and utilizing traditional channels of communication within these communities.

Zonal control on Holocene precipitation in northwestern Madagascar based on a stalagmite from Anjohibe.

The Malagasy Summer Monsoon is an important part of the larger Indian Ocean and tropical monsoon region. As the effects of global warming play out, changes to precipitation in Madagascar will have important ramifications for the Malagasy people. To help understand how precipitation responds to climate changes we present a long-term Holocene speleothem record from Anjohibe, part of the Andranoboka cave system in northwestern Madagascar. To date, it is the most complete Holocene record from this region and sheds light on the nature of millennial and centennial precipitation changes in this region. We find that over the Holocene, precipitation in northwestern Madagascar is actually in phase with the Northern Hemisphere Asian monsoon on multi-millennial scales, but that during some shorter centennial-scale events such as the 8.2 ka event, Anjohibe exhibits an antiphase precipitation signal to the Northern Hemisphere. The ultimate driver of precipitation changes across the Holocene does not appear to be the meridional migration of the monsoon. Instead, zonal sea surface temperature gradients in the Indian Ocean seem to play a primary role in precipitation changes in northwestern Madagascar.

Characterization of a compressive imaging system using laboratory and natural light scenes.

Compressive imagers acquire images, or other optical scene information, by a series of spatially filtered intensity measurements, where the total number of measurements required depends on the desired image quality. Compressive imaging (CI) offers a versatile approach to optical sensing which can improve size, weight, and performance (SWaP) for multispectral imaging or feature-based optical sensing. Here we report the first (to our knowledge) systematic performance comparison of a CI system to a conventional focal plane imager for binary, grayscale, and natural light (visible color and infrared) scenes. We generate 1024×1024 images from a range of measurements (0.1%-100%) acquired using digital (Hadamard), grayscale (discrete cosine transform), and random (Noiselet) CI basis sets. Comparing the outcome of the compressive images to conventionally acquired images, each made using 1% of full sampling, we conclude that the Hadamard Transform offered the best performance and yielded images with comparable aesthetic quality and slightly higher spatial resolution than conventionally acquired images.