Abrupt transitions in a southwest USA desert grassland related to the Pacific Decadal Oscillation.

Prediction of abrupt ecosystem transitions resulting from climatic change will be an essential element of adaptation strategies in the coming decades. In the arid southwest USA, the collapse and recovery of long-lived perennial grasses have important effects on ecosystem services, but the causes of these variations have been poorly understood. Here we use a quality-controlled vegetation monitoring dataset initiated in 1915 to show that grass cover dynamics during the 20th century were closely correlated to the Pacific decadal oscillation (PDO) index. The relationship out-performed models correlating grasses to yearly precipitation and drought indices, suggesting that ecosystem transitions attributed only to local disturbances were instead influenced by climate teleconnections. Shifts in PDO phase over time were associated with the persistent loss of core grass species and recovery of transient species, so recovery of grasses in aggregate concealed significant changes in species composition. However, the relationship between PDO and grass cover broke down after 1995; grass cover is consistently lower than PDO would predict. The decoupling of grass cover from the PDO suggests that a threshold had been crossed in which warming or land degradation overwhelmed the ability of any grass species to recover during favorable periods.

Global distribution, trends, and drivers of flash drought occurrence.

Flash drought is characterized by a period of rapid drought intensification with impacts on agriculture, water resources, ecosystems, and the human environment. Addressing these challenges requires a fundamental understanding of flash drought occurrence. This study identifies global hotspots for flash drought from 1980-2015 via anomalies in evaporative stress and the standardized evaporative stress ratio. Flash drought hotspots exist over Brazil, the Sahel, the Great Rift Valley, and India, with notable local hotspots over the central United States, southwestern Russia, and northeastern China. Six of the fifteen study regions experienced a statistically significant increase in flash drought during 1980-2015. In contrast, three study regions witnessed a significant decline in flash drought frequency. Finally, the results illustrate that multiple pathways of research are needed to further our understanding of the regional drivers of flash drought and the complex interactions between flash drought and socioeconomic impacts.

Nanoscale characteristics of conditioning film development on photobioreactor materials: influence on the initial adhesion and biofilm formation by a cyanobacterium.

Adsorption of conditioning films on a solid surface is the first step in the development of biofilms. With the goal of understanding the preliminary adhesion mechanisms of cyanobacteria on photobioreactor (PBR) materials to prevent biofouling, the physical changes occurring on PBR materials were investigated during the initial adhesion and biofilm formation by Anabaena sp. PCC 7120, a cyanobacterium that is genetically modified to produce linalool. Atomic force microscopy (AFM) revealed that the conditioning film deposition was in the form of spike-like structures on all the materials except PVC. The average heights (in the range 9 - 16 nm) of the conditioning films deposited on glass, PMMA, PC and HDPE were 11 to 20 times higher than on PVC at 96 h. The time dependent change in thickness of conditioning films correlated well with Anabaena cell attachment to the PBR materials. The rapid and significant colonization of Anabaena on glass within 48 h was consistent with the increase in thickness of the conditioning film within this time period. Lack of the conditioning film spike structures and no change in thickness of the conditioning films with time on the PVC together with comparatively delayed cell attachment and conditioning-film protein deposition on this material, indicated that the nanoscale spike structures on the other PBR materials may be accelerating the cell attachment process but are not a prerequisite for cell attachment. These results suggest that PVC should be explored further as an antifouling material for photobioreactors. The thickness of the conditioning films on glass measured by a scratch and scan method was in good agreement with the thickness values measured by an adhesive tape method, indicating that both these methods can be used for fast and reliable AFM thickness determination of bacterial conditioning films.

Preoperative Patient-Reported Outcomes Measurement Information System Global Health Scores Predict Patients Achieving the Minimal Clinically Important Difference in the Early Postoperative Time Period After Total Knee Arthroplasty.

INTRODUCTION: The patient-specific factors influencing postoperative improvement after total knee arthroplasty (TKA) are important considerations for the surgeon and patient. The primary purpose of this study was to determine which patient demographic factors influence the postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health (GH) scores. In addition, we aimed to compare the prognostic utility of preoperative PROMIS-GH scores and the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) in predicting postoperative improvement. METHODS: This retrospective cohort study of a consecutive series of patients who underwent primary, unilateral TKA analyzed prospectively collected KOOS-JR and PROMIS-GH surveys. PROMIS-GH includes physical health (PH) and mental health scores. Patient demographic and presurgical characteristics were evaluated for prognostic capability in predicting postoperative improvement in the PROMIS scores and achievement of the minimal clinically important difference (MCID). Receiver operating characteristic curves were used to understand the prognostic thresholds of the preoperative PROMIS score and KOOS-JR for predicting MCID achievement. RESULTS: A total of 872 patients were included. Although unadjusted analyses showed associations between patient demographic factors and PROMIS-PH scores, multivariable regression analysis for predictors of MCID achievement demonstrated that PROMIS-PH was the only significant preoperative variable. Receiver operating characteristic analysis revealed that the area under the curve of PROMIS-PH (0.70; 95% CI, 0.67 to 0.74) was less than that of the KOOS-JR (0.77; 95% CI, 0.73 to 0.81; P = 0.032). Sensitivity and specificity for achieving the MCID were maximized for preoperative PROMIS-PH scores of ≤ 38 (59% and 70%) and for preoperative KOOS-JR ≤ 51 (71% and 69%). CONCLUSIONS: Preoperative KOOS-JR and PROMIS-PH scores predict clinically meaningful improvement after TKA. The KOOS-JR has greater prognostic utility in the early postoperative period. LEVEL OF EVIDENCE: Level III, Prognostic Study.

Minimal Clinically Important Difference in Robotic-Assisted Total Knee Arthroplasty Versus Standard Manual Total Knee Arthroplasty.

BACKGROUND: The purpose of this study was to determine whether robotic total knee arthroplasty (R-TKA) demonstrated evidence of improvement in minimal clinically important difference (MCID) in early (<4 weeks) and intermittent (4-8 month) patient-reported outcomes compared with manual total knee arthroplasty (M-TKA). METHODS: A prospectively collected database was reviewed of 1160 consecutive patients undergoing R-TKA or M-TKA from December 2017 to October 2019. Primary outcomes consisted of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and Patient-Reported Outcomes Measurement Information System Global Health Measures of Physical Health (PH) and Mental Health (MH). Statistical analysis included MCID via the distribution method. RESULTS: Univariate analysis demonstrated conflicting results for early MCID achievement favoring M-TKA (4-week KOOS-JR, P = .03) for the multisurgeon cohort, but favored R-TKA (4-week Patient-Reported Outcomes Measurement Information System-PH, P = .04) in the single-surgeon analysis, and the remaining outcome scores were similar. Ultimately, multivariate analysis demonstrated similar 4-week and 6-month MCID achievement in all measures. Lower preoperative scores consistently achieved MCID at a higher rate in M-TKA, although in R-TKA, the higher baseline scores improved at a rate comparable with those with lower scores in all but the short-term postoperative KOOS-JR. CONCLUSION: R-TKA demonstrated comparable MCID achievement to M-TKA across the larger cohort. Single-surgeon comparison did show some early benefit. Confounding variables such as surgical technique, implant fixation, and responsiveness of an outcome measure may be as important as simply what tools are used during surgery. Such granular data should be sought out in future studies.

Clinical and laboratory impact of concomitant syphilis infection during acute HIV.

INTRODUCTION: Cognitive impairment has been reported in people living with HIV-1 (PLWH) with prior syphilis, while PLWH who present with incident syphilis have reduced blood CD4 T-lymphocyte and elevated HIV-1 RNA levels. However, the clinical, virological and neurocognitive effects of syphilis during acute HIV-1 (AHI) remain unknown. METHODS: Pre-antiretroviral therapy laboratory outcomes and neurocognitive performance in a four-test battery in the SEARCH10/RV254 AHI cohort were compared according to syphilis status, determined by serum Treponema pallidum haemagglutination (TPHA), Venereal Disease Research Laboratory (VDRL) and syphilis treatment history. Impaired cognitive performance was defined as having z-scores ≤ -1 in at least two tests or ≤ -2 in at least one test. RESULTS: Out of 595 AHI participants (97% male, median age of 26 years and estimated duration of HIV-1 infection of 19 days), 119 (20%) had history of syphilis (TPHA-positive), of whom 51 (9%) had untreated syphilis (TPHA-positive/VDRL-positive/without prior treatment). Compared with those without syphilis (TPHA-negative), individuals with untreated syphilis had higher CD8 T-lymphocyte levels but not higher plasma HIV-1 RNA or lower CD4 T-lymphocyte levels. Taking into account estimated duration of HIV-1 infection (P < 0.001), and later Fiebig stages (III-V) (P < 0.001), those with untreated syphilis had higher CD8 T-lymphocyte levels (P = 0.049). Individuals with any syphilis (TPHA-positive), but not untreated syphilis, had higher odds of impaired cognitive performance than those without (P = 0.002). CONCLUSIONS: During AHI, individuals with any history of syphilis (TPHA-positive) had poorer cognitive performance than those without syphilis. However, syphilis was not associated with worsened HIV disease measures as described in chronic infection.

Conditioning film formation and its influence on the initial adhesion and biofilm formation by a cyanobacterium on photobioreactor materials.

Although cyanobacteria are a common group of microorganisms well-suited to utilization in photobioreactors (PBRs), studies of cyanobacteria fouling and its prevention are scarce. Using a cyanobacterium, Anabaena sp. PCC 7120, which had been genetically modified to enhance linalool production, the formation of conditioning films and the effects of these on the physico-chemical surface properties of various PBR materials during initial adhesion and biofilm formation were investigated. The adhesion assay revealed that the overall attachment of Anabaena was substratum dependent and no correlation between the hydrophobicity/roughness of clean material and cell attachment was found. Surface hydrophilicity/hydrophobicity of all the materials changed within 12 h due to formation of conditioning films. ATR-FTIR spectroscopy revealed that the fractional change in protein deposition between 12 to 96 h was consistent with Anabaena cell attachment but polysaccharide deposition was material specific and did not correlate with cell attachment on the PBR materials. Also, the delay in conditioning film proteins on PVC and PTFE indicated that components other than proteins may be responsible for the decrease in contact angles on these surfaces within 12 h. This indicates the important role of the chemical nature of adsorbed conditioning films in determining the initial attachment of Anabaena to PBR materials. The lower rate of attachment of Anabaena on the hydrophilic surfaces (glass and PMMA) between 72 h to 96 h (regime 3) showed that these surfaces could potentially have low fouling characteristics at extended time scales and should be considered for further research.

Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Short Forms Demonstrate Responsiveness in Patients Undergoing Knee Arthroplasty.

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) is an alternative to legacy outcome metrics. We investigated the relationship between Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS-JR) and PROMIS Global Health forms of Physical Health (PH) and Mental Health (MH) in knee arthroplasty patients. METHODS: This is a retrospective cohort study of knee arthroplasty patients from December 2017 through April 2019 who had surveys collected preoperatively and postoperatively. We excluded patients undergoing revision surgery. Outcome scores were analyzed for responsiveness, effect size index (ESI), minimal clinically important difference (MCID), and correlation with each other through 12 months postoperatively. RESULTS: A total of 875 patients were included. Floor and ceiling effects were 0% for PROMIS-PH. Postoperative PROMIS-PH and KOOS-JR scores significantly correlated with one another and increased from baseline at each postoperative time point (P < .001 for all). PROMIS-MH did not change between time points (P > .05). PROMIS-PH showed moderate responsiveness at 1 and 3 months (ESI >0.2) and excellent responsiveness at 6 and 12 months (ESI >0.8), whereas KOOS-JR was responsive at all time points (ESI >0.8). The MCID of PROMIS-PH correlated significantly with KOOS-JR, and a preoperative PROMIS-PH score of less than 32.5 predicted achieving MCID with 97% specificity. CONCLUSION: PROMIS global health forms are a valid metric which capture patient outcomes and correlate with KOOS-JR scores after knee arthroplasty. Although KOOS-JR may be more responsive in the early postoperative time period, both measures show excellent responsiveness at 6 and 12 months after knee arthroplasty.

HIVIS-DNA or HIVISopt-DNA priming followed by CMDR vaccinia-based boosts induce both humoral and cellular murine immune responses to HIV.

BACKGROUND: In order to develop a more effective prophylactic HIV-1 vaccine it is important optimize the components, improve Envelope glycoprotein immunogenicity as well as to explore prime-boost immunization schedules. It is also valuable to include several HIV-1 subtype antigens representing the world-wide epidemic. METHODS: HIVIS-DNA plasmids which include Env genes of subtypes A, B and C together with Gag subtypes A and B and RTmut/Rev of subtype B were modified as follows: the Envelope sequences were shortened, codon optimized, provided with an FT4 sequence and an immunodominant region mutated. The reverse transcriptase (RT) gene was shortened to contain the most immunogenic N-terminal fragment and fused with an inactivated viral protease vPR gene. HIVISopt-DNA thus contains fewer plasmids but additional PR epitopes compared to the native HIVIS-DNA. DNA components were delivered intradermally to young Balb/c mice once, using a needle-free Biojector® immediately followed by dermal electroporation. Vaccinia-based MVA-CMDR boosts including Env gene E and Gag-RT genes A were delivered intramuscularly by needle, once or twice. RESULTS: Both HIVIS-DNA and HIVISopt-DNA primed humoral and cell mediated responses well. When boosted with heterologous MVA-CMDR (subtypes A and E) virus inhibitory neutralizing antibodies were obtained to HIV-1 subtypes A, B, C and AE. Both plasmid compositions boosted with MVA-CMDR generated HIV-1 specific cellular responses directed against HIV-1 Env, Gag and Pol, as measured by IFNγ ELISpot. It was shown that DNA priming augmented the vector MVA immunological boosting effects, the HIVISopt-DNA with a trend to improved (Env) neutralization, the HIVIS-DNA with a trend to better (Gag) cell mediated immune reponses. CONCLUSIONS: HIVIS-DNA was modified to obtain HIVISopt-DNA that had fewer plasmids, and additional epitopes. Even with one DNA prime followed by two MVA-CMDR boosts, humoral and cell-mediated immune responses were readily induced by priming with either DNA construct composition. Priming by HIV-DNA augmented neutralizing antibody responses revealed by boosting with the vaccinia-based heterologous sequences. Cellular and antibody responses covered selected strains representing HIV-1 subtypes A, B, C and CRF01_AE. We assume this is related to the inclusion of heterologous full genes in the vaccine schedule.

Donors With Immune Thrombocytopenia: Do They Pose a Risk to Transplant Recipients?

Transplant-mediated alloimmune thrombocytopenia (TMAT) from donors with immune thrombocytopenia (ITP) can result in significant bleeding complications in the recipient. The risk to a recipient of TMAT if they receive an organ from a donor with ITP is unknown. The outcomes of recipients of organs from deceased donors with ITP recorded in the UK Transplant Registry between 2000 and 2015 were reviewed. Twenty-one deceased organ donors had a predonation diagnosis of ITP. These donors were significantly more likely to have died from intracranial hemorrhage than were all other deceased organ donors (85% vs. 57%, p < 0.001). Organs from donors with ITP resulted in 49 organ transplants (31 kidney, 14 liver, four heart), with only one case of TMAT, which occurred in a liver transplant recipient and resulted in death from bleeding complications 18 days posttransplantation. The recipient of a kidney from the same organ donor was not affected. Unadjusted 5-year patient and graft survival was significantly worse for liver transplant recipients from donors with ITP compared with liver transplant recipients from donors without ITP (64% vs. 85%, p = 0.012). Organs from donors with ITP may be considered for transplantation, but livers should be used with caution.

The FDA's sentinel initiative--A comprehensive approach to medical product surveillance.

In May 2008, the Department of Health and Human Services announced the launch of the Sentinel Initiative by the US Food and Drug Administration (FDA) to create the Sentinel System, a national electronic system for medical product safety surveillance. This system complements existing FDA surveillance capabilities that track adverse events reported after the use of FDA regulated products by allowing the FDA to proactively assess the safety of these products.

Topical vs Intravenous Tranexamic Acid in Primary Total Hip Arthroplasty: A Double-Blind, Randomized Controlled Trial.

BACKGROUND: Tranexamic acid (TXA) reduces perioperative blood loss in total hip arthroplasty (THA). METHODS: In our randomized control trial, 139 patients were enrolled and received 2 g of either topical or intravenous (IV) TXA. Preoperative and postoperative protocols were standardized. RESULTS: Calculated blood and Hgb loss were lower in the IV group (1195.0 ± 485.9 mL, 1442.7 ± 562.7 mL; P = .006), (160.3 [g] ± 63.8, 188.4 [g] ± 68.5; P = .014). There was a trend toward significance in transfusion reduction (11% [IV] vs 18% [topical]; P = .3). Both groups effectively reduced the transfusion rate. There was significant financial incentive for the use of TXA in THA with a savings of $314 per patient. CONCLUSIONS: IV and topical TXA are effective tools to reduce blood loss and transfusion costs in THA, and we recommend the IV form for ease of use.

Are you PEPped and PrEPped for travel? Risk mitigation of HIV infection for travelers.

The HIV pandemic persists globally and travelers are at risk for infection by the Human Immunodeficiency Virus (HIV). While HIV-focused guidelines delineate risk stratification and mitigation strategies for people in their home communities, travel issues are not addressed. In this review, direct and indirect evidence on HIV risk among travelers is explored. The burgeoning practice of employing pre-exposure prophylaxis (PrEP) with anti-retroviral therapy in the non-travel setting is introduced, as well as the more established use of post-exposure prophylaxis (PEP). Challenges in applying these lessons to travelers are discussed, and a new guidelines process is scoped and recommended.

A prospective double-blind placebo controlled trial of topical tranexamic acid in total knee arthroplasty.

Tranexamic acid (TNA) reduces postoperative blood loss in general and obstetrical surgery but there is limited orthopaedic literature regarding its use in the topical setting. To study the effect of topical TNA after primary total knee arthroplasty (TKA), 101 patients were randomized to topical administration of 2.0g TNA in 75mL of normal saline (50 patients) or placebo (51 patients). Operative technique, drug administration, and venous thromboembolism prophylaxis were standardized. All patients underwent screening ultrasound of the operative extremity. Total blood loss was lower in the TNA group (940.2±327.1mL) than the placebo group (1293.1±532.7mL)(P<0.001), and four patients in the placebo group and none in the TNA group received postoperative transfusion (P=0.118). We recommend administration of topical TNA in primary TKA in healthy patients to decrease perioperative blood loss.

Diabetes educators' knowledge, opinions and behaviors regarding periodontal disease and diabetes.

PURPOSE: The purpose of this study was to determine certified diabetes educators' (CDE) knowledge, behaviors and opinions about periodontal disease and diabetes. METHODS: A 33 item questionnaire was distributed to CDEs who provide counseling and education services to patients with diabetes. Questions were open and closed-ended and Likert-scale. A total of 298 CDEs participated in the survey. Descriptive statistics were utilized. RESULTS: Most (62%) agreed that CDEs need to collaborate with dental professionals in disease management and 84% indicated interest in an oral health component being added to their continuing education. Only 20% felt confident in providing an oral health screening to their patients, while 51% discussed oral health with their patients and 64% said they have referred a patient to a dentist within the past year. Most (79%) have not received formal oral health education. CONCLUSION: The findings indicate that CDEs are aware of and agree that there is a link between oral health and systemic health and that collaboration with the dental profession would be a positive outcome for their patients, as would oral health topics being added to their continuing education courses. By introducing inter-professional collaboration between dental professionals and CDEs, and adding an oral health component to CE courses, CDEs' ability to educate their patients regarding the oral/systemic link could improve.

6-Aryl-3-pyrrolidinylpyridines as mGlu5 receptor negative allosteric modulators.

A series of 6-aryl-3-pyrrolidinylpyridine analogs was explored as structurally novel negative allosteric modulators of the mGlu5 receptor lacking an alkyne or oxadiazole moiety. Compounds in this series were characterized by tractable SAR, good in vitro potencies and brain penetration in rodents.

North Carolina internists' and endocrinologists' knowledge, opinions, and behaviors regarding periodontal disease and diabetes: need and opportunity for interprofessional education.

The aim of this study was to determine the knowledge and practice behaviors of one state's internists and endocrinologists who treat patients with any type of diabetes. A thirty-five-item questionnaire was mailed to 1,000 internists and 115 endocrinologists in North Carolina. Questions were open and closed ended and Likert-scaled. Descriptive statistics and bivariate analysis were utilized. The response rate was 34 percent (N=378). The overall usable response rate was 23 percent (N=254). Over half of the respondents (66 percent) were males. Internists' and endocrinologists' knowledge about periodontal disease was high. The majority of the respondents agreed that physicians should be taught about periodontal disease (88 percent) and should be trained to screen for periodontal disease in their patients (78 percent). However, when asked if they are confident in providing an oral health screening for their patients, the responses were evenly distributed from strongly agree to strongly disagree. This study suggests that internists and endocrinologists have some knowledge about oral health and believe that there is a link between periodontal disease and diabetes mellitus; however, the majority do not have sufficient familiarity with the studies that link periodontal disease and diabetes mellitus. They agree with the idea of collaboration with dental professionals to reduce the number of patients at risk for developing periodontal disease. Perhaps the time is conducive to promote interprofessional education and collaboration between medical and dental health care providers to prepare for the future increase in patient and treatment needs.