Tropical Transpacific Shore Fishes

Tropical transpacific fishes occur on both sides of the world's largest deep-water barrier to the migration of marine shore organisms, the 4,000- to 7,000-km-wide Eastern Pacific Barrier (EPB). They include 64 epipelagic oceanic species and 126 species of shore fishes known from both the tropical eastern Pacific (TEP) and the central and West Pacific. The broad distributions of 19 of 39 circumglobal transpacific species of shore fishes offer no clues to the origin of their TEP populations; TEP populations of another 19 with disjunct Pacific distributions may represent isthmian relicts that originated from New World populations separated by the closure of the Central American isthmus. Eighty species of transpacific shore fishes likely migrated eastward to the TEP, and 22 species of shore fishes (12 of them isthmian relicts) and one oceanic species likely migrated westward from the TEP. Transpacific species constitute ~12% of the TEP's tropical shore fishes and 15-20% of shore fishes at islands on the western edge of the EPB. Eastward migrants constitute ~7% of the TEP's shore-fish fauna, and a similar proportion of TEP endemics may be derived from recent eastward immigration. Representation of transpacific species in different elements of the TEP fauna relates strongly to adult pelagic dispersal ability-they constitute almost all the epipelagic oceanic species, ~25% of the inshore pelagic species, but only 10% of the demersal shore fishes. Taxa that have multiple pelagic life-history stages are best represented among the transpacific species. Among demersal teleosts that have pelagic larvae, pelagic spawners are better represented than demersal spawners among transpacific species, perhaps because offshore larval development and longer pelagic larval durations provide the former with greater dispersal capabilities. There are strong phylogenetic effects on representation in the transpacific fauna: (1) elasmobranchs are proportionally better represented than teleosts, even teleosts with more pelagic life-history stages; (2) a pelagic juvenile stage with great dispersal potential allows tetraodontiforms that produce demersal or pelagic eggs to be well represented; and (3) various speciose central Pacific families with "adequate" larval dispersal characteristics lack transpacific species. El Niiios potentially enhance eastward migration by increasing eastward flow and halving transit times across the EPB. However, that effect may be offset by low productivity and high temperatures in those eastbound flows. There is little clear evidence of strongly increased migration across the EPB during El Niiios, including recent extreme events (1982-1983 and 1997-1998). During such events shore fishes in the TEP experience range expansions and become locally abundant at marginal areas such as the Galapagos, changes that can be confused with increased migration across the EPB. Although there is a strong bias toward eastward migration among the transpacific shore fishes, there likely is much more westward migration than previously realized: 20-25% of transpacific species may have migrated in that direction. Stronger eastbound than westbound currents can account for this bias. Westward migrants have better developed pelagic dispersal characteristics than many eastward migrants, suggesting that westward migration is more difficult. Many westward migrants associate with flotsam and flotsam-mediated migration is more likely to be westward. All westward migrants occur at Hawai'i, but only about one-fifth of them at the Marquesas. This bias may be due to: Hawai'i being a larger target and in the path of most of the flotsam dispersal from the TEP; an eastward current that impinges on the Marquesas, reducing westward arrivals; and most propagules dispersing toward the tropical Marquesas originating in the temperate eastern Pacific. However, the Hawaiian Islands also are much better sampled than the Marquesas. Although the TEP reef-fish fauna may be depauperate relative to that of the Indo-Malayan "center of diversity," it is as rich as the faunas of islands on the western side of the EPB. Hence a preponderance of eastward migration does not represent a response to a richness gradient across that barrier. There is little evidence that a paucity of ecological groups in the native TEP fauna is primarily responsible for the structure of the eastward-migrant fauna. Rather, eastward migrants may simply represent a cross section of those in the donor fauna, tempered by phylogenetic variation in dispersal ability. Because few central Pacific fishes can live only on live corals and coral reefs, the rarity of such reefs in the TEP is unlikely to strongly limit eastward migration. Differences between oceanic and adjacent continental reef-fish faunas in the West Pacific indicate that each is strongly tied to its respective habitat. Hence, the rarity in the TEP of the (overwhelmingly) most abundant habitat present in the central Pacific-tropical oceanic reefs-may strongly limit migration in both directions across the EPB: there is little suitable habitat for eastward migrants in the TEP and few suitable species and tiny source populations for westward migrants. The global effects that oceanic/continental habitat differences have on reef-fish biogeography need further assessment. Genetic data on ~18% of the transpacific species indicate: that conspecific populations of oceanic species (especially) and shore fishes are genetically well connected across the EPB; that circumtropical taxa in the TEP include isolated isthmian relicts and recent eastward migrants; that all five TEP species of one circumtropical genus (Thalassoma) were derived by several eastward invasions after the closure of the Isthmus of Panama; that some isolated Hawaiian central Pacific populations were established by postisthmian invasion from the TEP; and that Indo-central Pacific species unsuspectedly can co-occur with their endemic sibling sisters in the TEP. Genetic data support distributional data that indicate a strong preponderance of eastward migration across the EPB but also more westward migration than previously thought. Future genetic studies should resolve a question that distributional data cannot: how many widespread presumed eastward-migrant transpacific species actually originated by westward migration from the TEP

Differential Single-stranded DNA Binding Properties of the Paralogous SsbA and SsbB Proteins from Streptococcus pneumoniae

The naturally transformable Gram-positive bacterium Streptococcus pneumoniae has two single-stranded DNA-binding (SSB) proteins, designated SsbA and SsbB. The SsbA protein is similar in size to the well characterized SSB protein from Escherichia coli (SsbEc). The SsbB protein, in contrast, is a smaller protein that is specifically induced during natural transformation and has no counterpart in E. coli. In this report, the single-stranded DNA (ssDNA) binding properties of the SsbA and SsbB proteins were examined and compared with those of the SsbEc protein. The ssDNA binding characteristics of the SsbA protein were similar to those of the SsbEc protein in every ssDNA binding assay used in this study. The SsbB protein differed from the SsbA and SsbEc proteins, however, both in its binding to short homopolymeric dT(n) oligomers (as judged by polyacrylamide gel-shift assays) and in its binding to the longer naturally occurring X and M13 ssDNAs (as judged by agarose gel-shift assays and electron microscopic analysis). The results indicate that an individual SsbB protein binds to ssDNA with an affinity that is similar or higher than that of the SsbA and SsbEc proteins. However, the manner in which multiple SsbB proteins assemble onto a ssDNA molecule differs from that observed with the SsbA and SsbEc proteins. These results represent the first analysis of paralogous SSB proteins from any bacterial species and provide a foundation for further investigations into the biological roles of these proteins

Physical Aspects of Healthy Aging: Assessments of Three Measures of Balance for Studies in Middle-Aged and Older Adults

Objectives. To investigate the reliability and correlations with age of the balance components of the EPESE, NHANES, and the Good Balance Platform System (GBPS) in a normal population of adults. Design. Cross-sectional. Setting. Urban Medical Center in the Pacific. Participants. A random sample of 203 healthy offspring of Honolulu Heart Program participants, ages 38–71. Measurements. Subjects were examined twice at visits one week apart using the balance components of the EPESE, NHANES, and the good balance system tests. Results. The EPESE and NHANES batteries of tests were not sufficiently challenging to allow successful discrimination among subjects in good health, even older subjects. The GBPS allowed objective quantitative measurements, but the test-retest correlations generally were not high. The GBPS variables correlated with age only when subjects stood on a foam pad; they also were correlated with anthropometric variables. Conclusion. Both EPESE and NHANES balance tests were too easy for healthy subjects. The GBPS had generally low reliability coefficients except for the most difficult testing condition (foam pad, eyes closed). Both height and body fat were associated with GBPS scores, necessitating adjusting for these variables if using balance as a predictor of future health

Crowdsourced assessment of surgical skill proficiency in cataract surgery

OBJECTIVE: To test whether crowdsourced lay raters can accurately assess cataract surgical skills. DESIGN: Two-armed study: independent cross-sectional and longitudinal cohorts. SETTING: Washington University Department of Ophthalmology. PARTICIPANTS AND METHODS: Sixteen cataract surgeons with varying experience levels submitted cataract surgery videos to be graded by 5 experts and 300+ crowdworkers masked to surgeon experience. Cross-sectional study: 50 videos from surgeons ranging from first-year resident to attending physician, pooled by years of training. Longitudinal study: 28 videos obtained at regular intervals as residents progressed through 180 cases. Surgical skill was graded using the modified Objective Structured Assessment of Technical Skill (mOSATS). Main outcome measures were overall technical performance, reliability indices, and correlation between expert and crowd mean scores. RESULTS: Experts demonstrated high interrater reliability and accurately predicted training level, establishing construct validity for the modified OSATS. Crowd scores were correlated with (r = 0.865, p \u3c 0.0001) but consistently higher than expert scores for first, second, and third-year residents (p \u3c 0.0001, paired t-test). Longer surgery duration negatively correlated with training level (r = -0.855, p \u3c 0.0001) and expert score (r = -0.927, p \u3c 0.0001). The longitudinal dataset reproduced cross-sectional study findings for crowd and expert comparisons. A regression equation transforming crowd score plus video length into expert score was derived from the cross-sectional dataset (r CONCLUSIONS: Crowdsourced rankings correlated with expert scores, but were not equivalent; crowd scores overestimated technical competency, especially for novice surgeons. A novel approach of adjusting crowd scores with surgery duration generated a more accurate predictive model for surgical skill. More studies are needed before crowdsourcing can be reliably used for assessing surgical proficiency

Leptin mediates the increase in blood pressure associated with obesity.

Obesity is associated with increased blood pressure (BP), which in turn increases the risk of cardiovascular diseases. We found that the increase in leptin levels seen in diet-induced obesity (DIO) drives an increase in BP in rodents, an effect that was not seen in animals deficient in leptin or leptin receptors (LepR). Furthermore, humans with loss-of-function mutations in leptin and the LepR have low BP despite severe obesity. Leptin's effects on BP are mediated by neuronal circuits in the dorsomedial hypothalamus (DMH), as blocking leptin with a specific antibody, antagonist, or inhibition of the activity of LepR-expressing neurons in the DMH caused a rapid reduction of BP in DIO mice, independent of changes in weight. Re-expression of LepRs in the DMH of DIO LepR-deficient mice caused an increase in BP. These studies demonstrate that leptin couples changes in weight to changes in BP in mammalian species

Genome-wide association study identifies 30 loci associated with bipolar disorder.

Bipolar disorder is a highly heritable psychiatric disorder. We performed a genome-wide association study (GWAS) including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 variants with P < 1 × 10-4 in an additional 9,412 cases and 137,760 controls. Eight of the 19 variants that were genome-wide significant (P < 5 × 10-8) in the discovery GWAS were not genome-wide significant in the combined analysis, consistent with small effect sizes and limited power but also with genetic heterogeneity. In the combined analysis, 30 loci were genome-wide significant, including 20 newly identified loci. The significant loci contain genes encoding ion channels, neurotransmitter transporters and synaptic components. Pathway analysis revealed nine significantly enriched gene sets, including regulation of insulin secretion and endocannabinoid signaling. Bipolar I disorder is strongly genetically correlated with schizophrenia, driven by psychosis, whereas bipolar II disorder is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential biological mechanisms for bipolar disorder

Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

Presidential Commission on the Supreme Court of the United States Final Report

On April 9, 2021, President Joseph R. Biden, Jr. issued Executive Order 14023 establishing this Commission, to consist of “individuals having experience with and knowledge of the Federal judiciary and the Supreme Court of the United States.” The Order charged the Commission with producing a report for the President that addresses three sets of questions. First, the Report should include “[a]n account of the contemporary commentary and debate about the role and operation of the Supreme Court in our constitutional system and about the functioning of the constitutional process by which the President nominates and, by and with the advice and consent of the Senate, appoints Justices to the Supreme Court.” Second, the Report should consider the “historical background of other periods in the Nation’s history when the Supreme Court’s role and the nominations and advice-and-consent process were subject to critical assessment and prompted proposals for reform.” Third, the Report should provide an analysis of the principal arguments for and against particular proposals to reform the Supreme Court, “including an appraisal of [their] merits and legality,” and should be informed by “a broad spectrum of ideas.” The Report begins by explaining the genesis of today’s Court reform debate, including by identifying developments that gave rise to President Biden’s decision to issue the April 2021 Executive Order, particularly the debates surrounding the most recent nominations. This Introduction emphasizes that the Court’s composition and jurisprudence long have been subjects of public controversy and debate in the nation’s civic life: The Court serves as a crucial guardian of the rule of law and also plays a central role in major social and political conflicts. Its decisions have profound effects on the life of the nation. Though conflict surrounding the processes by which the President nominates and the Senate confirms Justices is not new, it has become more intensely partisan in recent years. The Introduction also articulates three common and interrelated ideas frequently invoked in reform debates and throughout the Chapters of the Report: the importance of protecting or enhancing the Court’s legitimacy; the role of judicial independence in our system of government; and the value of democracy and its relationship to the Supreme Court’s decisionmaking. These important ideas can mean different things to different people. The Introduction discusses the range of meanings ascribed to these terms, with the aim of clarifying how they are deployed in arguments for and against reform