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In a recent study, visual signals were recorded for the first time in starburst amacrine cells of the macaque retina, and, as for mouse and rabbit, a directional bias observed in calcium signals was recorded from near the dendritic tips. Stimulus motion from the soma toward the tip generated a larger calcium signal than motion from the tip toward the soma. Two mechanisms affecting the spatiotemporal summation of excitatory postsynaptic currents have been proposed to contribute to directional signaling at the dendritic tips of starbursts: (1) a “morphological” mechanism in which electrotonic propagation of excitatory synaptic currents along a dendrite sums bipolar cell inputs at the dendritic tip preferentially for stimulus motion in the centrifugal direction; (2) a “space–time” mechanism that relies on differences in the time-courses of proximal and distal bipolar cell inputs to favor centrifugal stimulus motion. To explore the contributions of these two mechanisms in the primate, we developed a realistic computational model based on connectomic reconstruction of a macaque starburst cell and the distribution of its synaptic inputs from sustained and transient bipolar cell types. Our model suggests that both mechanisms can initiate direction selectivity in starburst dendrites, but their contributions differ depending on the spatiotemporal properties of the stimulus. Specifically, the morphological mechanism dominates when small visual objects are moving at high velocities, and the space–time mechanism contributes most for large visual objects moving at low velocities.
The Late Ordovician (late Katian) Tcherskidium fauna consisted of large- and thick-shelled virgianid pentamerid brachiopods characterized by large and ribbed shells of Tcherskidium and Proconchidium and usually associated with Holorhynchus, Deloprosopus, and Eoconchidium. This unique fauna was widely distributed across several tectonic plates, largely confined to the paleoequatorial and especially the northern paleotropical zones, such as northern Laurentia, accretionary terranes of Alaska, Kolyma, Baltica, Siberia, Kazakh and adjacent terranes, and South China. In Laurentia, the eponymous genus Tcherskidium was predominant in regions north of the paleoequator and, in sharp contrast, was absent south of the paleoequator. In this study, Tcherskidium lonei n. sp. and Proconchidium schleyi n. sp. are described from Alaska and North Greenland, respectively, adding new data on the Tcherskidium fauna of the Late Ordovician Northern Hemisphere. Shell gigantism, together with the sharp paleobiogeographic division, suggests that the Late Ordovician (late Katian) Northern Hemisphere had a prevailing warm-water mass, probably due to the lack of large landmass beyond the northern tropics. This was in sharp contrast to the Southern Hemisphere, which was frequently influenced by cold-water invasions from the ice-bearing Gondwana supercontinent centered on the South Pole.
Among 287 US hospitals reporting data between 2015 and 2018, annual pediatric surgical site infection (SSI) rates ranged from 0% for gallbladder to 10.4% for colon surgeries. Colon, spinal fusion, and small-bowel SSI rates did not decrease with greater surgical volumes in contrast to appendix and ventricular-shunt SSI rates.
Modular coral-like fossils occur in thrombolitic reefal beds at two stratigraphic levels within the Lower Ordovician (Floian) Barbace Cove Member of the Boat Harbour Formation, in the St. George Group of western Newfoundland. They are here assigned to Reptamsassia n. gen.; R. divergens n. gen. n. sp. is present at both levels, whereas a comparatively small-module species, R. minuta n. gen. n. sp., is confined to the upper level. Reptamsassia n. gen. resembles the Ordovician genus Amsassia in its phacelocerioid structure, back-to-back walls of adjoining modules, module increase by longitudinal fission involving infoldings of the wall, tabula-like structures that are continuous with the vertical module wall, and calices with concave-up bottoms. The new genus is differentiated by its encrusting habit, modules with highly variable growth directions and shapes throughout skeletal growth, and modules that may separate slightly or diverge from one another following fission. Together, Amsassia and Reptamsassia n. gen. are considered to represent a distinct group of calcareous algae, the Amsassiaceae n. fam., which possibly belongs to the green algae. The Early Ordovician origination of Amsassia followed by Reptamsassia n. gen. contributed to the beginning of the rise in diversity on a global scale and in reefal settings during the Great Ordovician Biodiversification Event. Reptamsassia minuta n. gen. n. sp. was an obligate symbiont that colonized living areas on its host, R. divergens n. gen. n. sp., with isolated modules of R. divergens n. gen. n. sp. able to persist in the resulting intergrowth with R. minuta n. gen. n. sp. This is the earliest known symbiotic intergrowth of macroscopic modular species, exemplifying the development of ecologic specialization and ecosystem complexity in Early Ordovician reefs.
Modular coral-like fossils from Lower Ordovician (Tremadocian) thrombolitic mounds in the St. George Group of western Newfoundland were initially identified as Lichenaria and thought to include the earliest tabulate corals. They are here assigned to Amsassia terranovensis n. sp. and Amsassia? sp. A from the Watts Bight Formation, and A. diversa n. sp. and Amsassia? sp. B from the overlying Boat Harbour Formation. Amsassia terranovensis n. sp. and A. argentina from the Argentine Precordillera are the earliest representatives of the genus. Amsassia is considered to be a calcareous alga, possibly representing an extinct group of green algae. The genus originated and began to disperse in the Tremadocian, during the onset of the Great Ordovician Biodiversification Event, on the southern margin of Laurentia and the Cuyania Terrane. It inhabited small, shallow-marine reefal mounds constructed in association with microbes. The paleogeographic range of Amsassia expanded in the Middle Ordovician (Darriwilian) to include the Sino-Korean Block, as well as Laurentia, and its environmental range expanded to include non-reefal, open- and restricted-marine settings. Amsassia attained its greatest diversity and paleogeographic extent in the Late Ordovician (Sandbian–Katian), during the culmination of the Great Ordovician Biodiversification Event. Its range included the South China Block, Tarim Block, Kazakhstan, and Siberia, as well as the Sino-Korean Block and Laurentia, and its affinity for small microbial mounds continued during that time. In the latest Ordovician (Hirnantian), the diversity of Amsassia was reduced, its distribution was restricted to non-reefal environments in South China, and it finally disappeared during the end-Ordovician mass extinction.
Tobacco smoking remains one of the leading causes of preventable illness and death and is heritable with complex underpinnings. Converging evidence suggests a contribution of the polygenic risk for smoking to the use of tobacco and other substances. Yet, the underlying brain mechanisms between the genetic risk and tobacco smoking remain poorly understood.
Genomic, neuroimaging, and self-report data were acquired from a large cohort of adolescents from the IMAGEN study (a European multicenter study). Polygenic risk scores (PGRS) for smoking were calculated based on a genome-wide association study meta-analysis conducted by the Tobacco and Genetics Consortium. We examined the interrelationships among the genetic risk for smoking initiation, brain structure, and the number of occasions of tobacco use.
A higher smoking PGRS was significantly associated with both an increased number of occasions of tobacco use and smaller cortical volume of the right orbitofrontal cortex (OFC). Furthermore, reduced cortical volume within this cluster correlated with greater tobacco use. A subsequent path analysis suggested that the cortical volume within this cluster partially mediated the association between the genetic risk for smoking and the number of occasions of tobacco use.
Our data provide the first evidence for the involvement of the OFC in the relationship between smoking PGRS and tobacco use. Future studies of the molecular mechanisms underlying tobacco smoking should consider the mediation effect of the related neural structure.
A Late Ordovician brachiopod fauna from the Black River quadrangle (D-1 1:63,360 scale) of east-central Alaska comprises taxa typical of the Late Ordovician brachiopod fauna in the pericratonic epeiric seas of Laurentia, including Hesperorthis pyramidalis (Twenhofel, 1928), Plaesiomys occidentalis (Okulitch, 1943), Eoplectodonta sp., Holtehdalina sp., Leptaena sp., Brevilamnulella minuta n. sp., Tcherskidium tenuicostatum n. sp., Rhynchotrema iowense Wang, 1949, and Whitfieldella sp. The presence of Plaesiomys occidentalis and Tcherskidium tenuicostata n. sp. indicates a latest Katian age by correlation with similar species in the Mackenzie Mountains, southern Manitoba, Anticosti Island, the American midcontinent, Kolyma, and Siberia. Cluster analysis based on 20 well-studied late Katian brachiopod faunas from various regions within Laurentia and elsewhere in other tectonic plates suggests that the small brachiopod faunule from Alaska has the strongest paleobiogeographic affinity with Laurentia, confirming that the Black River quadrangle of Alaska was part of Laurentia during the Late Ordovician.
The present study aims to investigate the effect of wholegrain and legume consumption on the incidence of age-related cataract in an older Australian population-based cohort. The Blue Mountains Eye Study (BMES) is a population-based cohort study of eye diseases among older adults aged 49 years or older (1992–1994, n 3654). Of 2334 participants of the second examination of the BMES (BMES 2, 1997–2000), 1541 (78·3 % of survivors) were examined 5 years later (BMES 3) who had wholegrain and legume consumption estimated from the FFQ at BMES 2. Cataract was assessed using photographs taken during examinations following the Wisconsin cataract grading system. Multivariable-adjusted logistic regression models were used to assess associations with the 5-year incidence of cataract from BMES 2 (baseline) to BMES 3. The 5-year incidence of cortical, nuclear and posterior subcapsular (PSC) cataract was 18·2, 16·5 and 5·9 %, respectively. After adjustment for age, sex and other factors, total wholegrain consumption at baseline was not associated with incidence of any type of cataract. High consumption of legumes showed a protective association for incident PSC cataract (5th quintile: adjusted OR 0·37; 95 % CI 0·15, 0·92). There was no significant trend of this association across quintiles (P = 0·08). In this older Australian population, we found no associations between wholegrain intake at baseline and the 5-year incidence of three cataract types. However, intake of legumes in the highest quintile, compared with the lowest quintile, may protect against PSC formation, a finding needing replication in other studies.
To investigate the impacts of depression screening, diagnosis and treatment on major adverse cardiac events (MACEs) in acute coronary syndrome (ACS).
Prospective cohort study including a nested 24-week randomised clinical trial for treating depression was performed with 5–12 years after the index ACS. A total of 1152 patients recently hospitalised with ACS were recruited from 2006 to 2012, and were divided by depression screening and diagnosis at baseline and 24-week treatment allocation into five groups: 651 screening negative (N), 55 screening positive but no depressive disorder (S), 149 depressive disorder randomised to escitalopram (E), 151 depressive disorder randomised to placebo (P) and 146 depressive disorder receiving medical treatment only (M).
Cumulative MACE incidences over a median 8.4-year follow-up period were 29.6% in N, 43.6% in S, 40.9% in E, 53.6% in P and 59.6% in M. Compared to N, screening positive was associated with higher incidence of MACE [adjusted hazards ratio 2.15 (95% confidence interval 1.63–2.83)]. No differences were found between screening positive with and without a formal depressive disorder diagnosis. Of those screening positive, E was associated with a lower incidence of MACE than P and M. M had the worst outcomes even compared to P, despite significantly milder depressive symptoms at baseline.
Routine depression screening in patients with recent ACS and subsequent appropriate treatment of depression could improve long-term cardiac outcomes.
Catheter-associated urinary tract infections in 592 hospitals immediately declined after federal value-based incentive program implementation, but this was fully attributable to a concurrent surveillance case definition revision. Post revision, more hospitals had favorable standardized infection ratios, likely leading to artificial inflation of their performance scores unrelated to changes in patient safety.
Many patients with advanced serious illness or at the end of life experience delirium, a potentially reversible form of acute brain dysfunction, which may impair ability to participate in medical decision-making and to engage with their loved ones. Screening for delirium provides an opportunity to address modifiable causes. Unfortunately, delirium remains underrecognized. The main objective of this pilot was to validate the brief Confusion Assessment Method (bCAM), a two-minute delirium-screening tool, in a veteran palliative care sample.
This was a pilot prospective, observational study that included hospitalized patients evaluated by the palliative care service at a single Veterans’ Administration Medical Center. The bCAM was compared against the reference standard, the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Both assessments were blinded and conducted within 30 minutes of each other.
We enrolled 36 patients who were a median of 67 years (interquartile range 63–73). The primary reasons for admission to the hospital were sepsis or severe infection (33%), severe cardiac disease (including heart failure, cardiogenic shock, and myocardial infarction) (17%), or gastrointestinal/liver disease (17%). The bCAM performed well against the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, for detecting delirium, with a sensitivity (95% confidence interval) of 0.80 (0.4, 0.96) and specificity of 0.87 (0.67, 0.96).
Significance of Results
Delirium was present in 27% of patients enrolled and never recognized by the palliative care service in routine clinical care. The bCAM provided good sensitivity and specificity in a pilot of palliative care patients, providing a method for nonpsychiatrically trained personnel to detect delirium.
Agetolites is a problematic Late Ordovician genus possessing traits of both tabulate and rugose corals. The presence of numerous mural pores has often been considered to indicate a relation to tabulates, although an affinity to rugosans has also been proposed, based mainly on well-developed septa that alternate in length. To further consider the taxonomic position of Agetolites, growth characteristics of coralla representing three species from the Xiazhen Formation in South China are documented and assessed, focusing on modes of corallite increase. Three major modes of increase are recognized. By far the most common mode involves the development of an offset from a connective mural pore, without a clear relationship to a particular parent corallite. This mode of increase is usually associated with corner pores, but in one case occurs at a wall pore. The lateral mode of increase, which is relatively uncommon, is a typical feature in corallites along the boundary of intergrowths with stromatoporoids. The axial mode of increase is rare, occurring during rejuvenation of a damaged corallite or during regeneration following termination of a corallite. The mode of corallite increase that is characteristic of Agetolites, involving a connective mural pore and occurring without evidence of a particular parent, supports the interpretation that this genus is not a rugosan or a typical favositid tabulate. Mural pores are unknown in rugosans, and offsets arise from distinct parent corallites in favositids. The Ordovician genus Lichenaria, considered a representative of the most primitive stock of tabulate corals, shows the closest similarities with types of increase in Agetolites. Certain aspects of lateral and axial increase in Agetolites are comparable to features in a few more genera of Ordovician tabulates, further supporting a tabulate affinity. The phylogenetic relation of Agetolites to those and other tabulate genera, however, remains unresolved.
National policies target healthcare-associated infections using medical claims and National Healthcare Safety Network surveillance data. We found low concordance between the 2 data sources in rates and rankings for surgical site infection following colon surgery in 155 hospitals, underscoring the limitations in evaluating hospital quality by claims data.
Based on multivariate morphometric analysis, Halysites catenularius is identified from the Rumba Formation (Telychian) and Jaagarahu Formation (Sheinwoodian) of Estonia; H. priscus is confirmed as a junior synonym. Halysites catenularius, H. junior, and H. senior are shown to be closely related; H. catenularius is morphologically intermediate. Cyclomorphism in H. catenularius, recorded by fluctuations of corallite tabularial area, indicates an average annual growth rate of 6.0 mm, which is typical for halysitids. Tubules in H. catenularius, generated from small intramural openings between adjacent corallites, were involved in two types of interstitial increase. The intramural openings, three types of lateral increase, temporary agglutinated patches of corallites, and axial increase documented in H. catenularius resemble features in some species of Catenipora. These similarities are consistent with the interpretation that Halysites evolved from Catenipora. Evaluation of the possibility that both genera are polyphyletic will require further detailed analysis of additional species.
Hill (Twin Research and Human Genetics, Vol. 21, 2018, 84–88) presented a critique of our recently published paper in Cell Reports entitled ‘Large-Scale Cognitive GWAS Meta-Analysis Reveals Tissue-Specific Neural Expression and Potential Nootropic Drug Targets’ (Lam et al., Cell Reports, Vol. 21, 2017, 2597–2613). Specifically, Hill offered several interrelated comments suggesting potential problems with our use of a new analytic method called Multi-Trait Analysis of GWAS (MTAG) (Turley et al., Nature Genetics, Vol. 50, 2018, 229–237). In this brief article, we respond to each of these concerns. Using empirical data, we conclude that our MTAG results do not suffer from ‘inflation in the FDR [false discovery rate]’, as suggested by Hill (Twin Research and Human Genetics, Vol. 21, 2018, 84–88), and are not ‘more relevant to the genetic contributions to education than they are to the genetic contributions to intelligence’.