Axis dependent conduction polarity in the air-stable semiconductor, PdSe2.

Axis-dependent conduction polarity (ADCP) is a unique electronic phenomena in which the charge polarity of carrier conduction can differ from p-type to n-type depending on the direction of travel through the crystal. Most materials that exhibit ADCP are metals, and very few semiconducting materials exhibit this effect. Here, we establish that PdSe2, a ∼0.5 eV band gap semiconductor that is air- and water-stable, exhibits ADCP, through the growth and characterization of the transport properties of crystals with extrinsic p- and n-type doping levels of Ir and Sb, respectively, in the 1016-1018 cm-3 range. Electron doped PdSe2 exhibits p-type conduction in the cross-plane direction and n-type conduction along the in-plane directions above an onset temperature of 100-200 K that varies with doping level. Lightly p-doped samples show p-type thermopower in all directions at low temperatures, but above ∼360 K the in-plane thermopower turns negative. Density functional theory calculations indicate that the origin of ADCP arises from the complementary effective mass anisotropies in the valence and conduction bands in this material, which facilitate hole transport in the cross-plane direction, and electron transport along the in-plane directions. ADCP occurs at temperatures with sufficient thermal population of both carrier types to overcome the extrinsic doping levels to exploit the effective mass anisotropy. In total, the development of this stable semiconductor in which thermally or optically excited holes and electrons inherently migrate along different directions opens up numerous potential applications in a multitude of technologies.

Suffering in silence: How COVID-19 school closures inhibit the reporting of child maltreatment.

To combat the spread of COVID-19, many primary and secondary schools in the United States canceled classes and moved instruction online. This study examines an unexplored consequence of COVID-19 school closures: the broken link between child maltreatment victims and the number one source of reported maltreatment allegations-school personnel. Using current, county-level data from Florida, we estimate a counterfactual distribution of child maltreatment allegations for March and April 2020, the first two months in which Florida schools closed. While one would expect the financial, mental, and physical stress due to COVID-19 to result in additional child maltreatment cases, we find that the actual number of reported allegations was approximately 15,000 lower (27%) than expected for these two months. We leverage a detailed dataset of school district staffing and spending to show that the observed decline in allegations was largely driven by school closures. Finally, we discuss policy implications of our findings for the debate surrounding school reopenings and suggest a number of responses that may mitigate this hidden cost of school closures.

Variable Refocusing Flip Angle Single-Shot Imaging for Sedation-Free Fast Brain MRI.

BACKGROUND AND PURPOSE: Conventional single-shot FSE commonly used for fast MRI may be suboptimal for brain evaluation due to poor image contrast, SNR, or image blurring. We investigated the clinical performance of variable refocusing flip angle single-shot FSE, a variation of single-shot FSE with lower radiofrequency energy deposition and potentially faster acquisition time, as an alternative approach to fast brain MR imaging. MATERIALS AND METHODS: We retrospectively compared half-Fourier single-shot FSE with half- and full-Fourier variable refocusing flip angle single-shot FSE in 30 children. Three readers reviewed images for motion artifacts, image sharpness at the brain-fluid interface, and image sharpness/tissue contrast at gray-white differentiation on a modified 5-point Likert scale. Two readers also evaluated full-Fourier variable refocusing flip angle single-shot FSE against T2-FSE for brain lesion detectability in 38 children. RESULTS: Variable refocusing flip angle single-shot FSE sequences showed more motion artifacts (P < .001). Variable refocusing flip angle single-shot FSE sequences scored higher regarding image sharpness at brain-fluid interfaces (P < .001) and gray-white differentiation (P < .001). Acquisition times for half- and full-Fourier variable refocusing flip angle single-shot FSE were faster than for single-shot FSE (P < .001) with a 53% and 47% reduction, respectively. Intermodality agreement between full-Fourier variable refocusing flip angle single-shot FSE and T2-FSE findings was near-perfect (κ = 0.90, κ = 0.95), with an 8% discordance rate for ground truth lesion detection. CONCLUSIONS: Variable refocusing flip angle single-shot FSE achieved 2× faster scan times than single-shot FSE with improved image sharpness at brain-fluid interfaces and gray-white differentiation. Such improvements are likely attributed to a combination of improved contrast, spatial resolution, SNR, and reduced T2-decay associated with blurring. While variable refocusing flip angle single-shot FSE may be a useful alternative to single-shot FSE and, potentially, T2-FSE when faster scan times are desired, motion artifacts were more common in variable refocusing flip angle single-shot FSE, and, thus, they remain an important consideration before clinical implementation.

Design of microresonators to minimize thermal noise below the standard quantum limit.

Microfabricated resonators play a crucial role in the development of quantum measurement, including future gravitational wave detectors. We use a micro-genetic algorithm and a finite element method to design a microresonator whose geometry is optimized to maximize the sub-Standard Quantum Limit (SQL) performance including lower thermal noise (TN) below the SQL, a broader sub-SQL region, and a sub-SQL region at lower frequencies. For the proposed design, we study the effects of different geometries of the mirror pad and cantilever microresonator on sub-SQL performance. We find that the maximum ratio of SQL to TN is increased, its frequency is decreased, and the sub-SQL range is increased by increasing the length of the microresonator cantilever, increasing the radius of the mirror pad, decreasing the width of the microresonator cantilever, and shifting the laser beam location from the mirror center. We also find that there exists a trade-off between the maximum ratio of SQL to TN and the sub-SQL bandwidth. The performance of this designed microresonator will allow it to serve as a test-bed for quantum non-demolition measurements and to open new regimes of precision measurement that are relevant for many practical sensing applications, including advanced gravitational wave detectors.

Independent or simultaneous lowering of core and skin temperature has no impact on self-paced intermittent running performance in hot conditions.

PURPOSE: To investigate the effects of lowering core (Tgi) and mean skin temperature (Tsk) concomitantly and independently on self-paced intermittent running in the heat. METHODS: 10 males (30.5 ± 5.8 years, 73.2 ± 14.5 kg, 176.9 ± 8.0 cm, 56.2 ± 6.6 ml/kg/min) completed four randomised 46-min self-paced intermittent protocols on a non-motorised treadmill in 34.4 ± 1.4 °C, 36.3 ± 4.6% relative humidity. 30-min prior to exercise, participants were cooled via either ice slurry ingestion (INT); a cooling garment (EXT); mixed-cooling (ice slurry and cooling garment concurrently) (MIX); or no-cooling (CON). RESULTS: At the end of pre-cooling and the start of exercise Tgi were lower during MIX (36.11 ± 1.3 °C) compared to CON (37.6 ± 0.5 °C) and EXT (36.9 ± 0.5 °C, p < 0.05). Throughout pre-cooling Tsk and thermal sensation were lower in MIX compared to CON and INT, but not EXT (p < 0.05). The reductions in thermophysiological responses diminished within 10-20 min of exercise. Despite lowering Tgi, Tsk, body temperature (Tb), and thermal sensation prior to exercise, the distances covered were similar (CON: 6.69 ± 1.08 km, INT: 6.96 ± 0.81 km, EXT: 6.76 ± 0.65 km, MIX 6.87 ± 0.70 km) (p > 0.05). Peak sprint speeds were also similar between conditions (CON: 25.6 ± 4.48 km/h, INT: 25.4 ± 3.6 km/h, EXT: 26.0 ± 4.94 km/h, MIX: 25.6 ± 3.58 km/h) (p > 0.05). Blood lactate, heart rate and RPE were similar between conditions (p > 0.05). CONCLUSION: Lowering Tgi and Tsk prior to self-paced intermittent exercise did not improve sprint, or submaximal running performance.

Stable isotopic characterization of a coastal floodplain forest community: a case study for isotopic reconstruction of Mesozoic vertebrate assemblages.

Stable isotopes are powerful tools for elucidating ecological trends in extant vertebrate communities, though their application to Mesozoic ecosystems is complicated by a lack of extant isotope data from comparable environments/ecosystems (e.g. coastal floodplain forest environments, lacking significant C4 plant components). We sampled 20 taxa across a broad phylogenetic, body size, and physiological scope from the Atchafalaya River Basin of Louisiana as an environmental analogue to the Late Cretaceous coastal floodplains of North America. Samples were analysed for stable carbon, oxygen and nitrogen isotope compositions from bioapatite and keratin tissues to test the degree of ecological resolution that can be determined in a system with similar environmental conditions, and using similar constraints, as those in many Mesozoic assemblages. Isotopic results suggest a broad overlap in resource use among taxa and considerable terrestrial-aquatic interchange, highlighting the challenges of ecological interpretation in C3 systems, particularly when lacking observational data for comparison. We also propose a modified oxygen isotope-temperature equation that uses mean endotherm and mean ectotherm isotope data to more precisely predict temperature when compared with measured Atchafalaya River water data. These results provide a critical isotopic baseline for coastal floodplain forests, and act as a framework for future studies of Mesozoic palaeoecology.

Insights about Fall Prevention of Older Adults in the State of Hawai'i.

The senior population in Hawai'i is growing at a dramatic pace. In the older population, falls and fall-related injuries are leading causes of morbidity and mortality. Moreover, the health care costs for falls are very high. The State of Hawai'i has taken measures to prevent falls through the promotion of medication reviews, vision checks, home assessments, and exercise. However, current published examinations of fall preventive measures have been insufficient, and more research is needed to confirm risk factors, effectiveness of preventive measures, and to explore future objectives. This paper examined the validity of fall risk factors and fall preventive measures for Hawai'i's seniors by conducting mail questionnaire surveys to a sample of seniors using medical alert services from one company in Hawai'i. The results of chi-square analysis suggest that having reduced ability to perform Activities of Daily Living (ADL) and reduced Instrumental Activities of Daily Living (IADL) were associated with a greater risk of falls (P < .01). In addition, those who fell were more likely to talk about fall preventions with their family members or friends and health providers compared with those who did not (P = .048 and .003, respectively). Evidence-based exercise programs for strengthening muscles and controlling physical balance may be needed to improve ADL and IADL. Furthermore, the results suggest that seniors do not accept that they are at risk of falling before they actually fall. Public health providers should consider how they approach seniors, and how they inform them of the importance of fall prevention across the life span.

Gut microbiota. Antimicrobial peptide resistance mediates resilience of prominent gut commensals during inflammation.

Resilience to host inflammation and other perturbations is a fundamental property of gut microbial communities, yet the underlying mechanisms are not well understood. We have found that human gut microbes from all dominant phyla are resistant to high levels of inflammation-associated antimicrobial peptides (AMPs) and have identified a mechanism for lipopolysaccharide (LPS) modification in the phylum Bacteroidetes that increases AMP resistance by four orders of magnitude. Bacteroides thetaiotaomicron mutants that fail to remove a single phosphate group from their LPS were displaced from the microbiota during inflammation triggered by pathogen infection. These findings establish a mechanism that determines the stability of prominent members of a healthy microbiota during perturbation.

The relationship between interleukin-6 in saliva, venous and capillary plasma, at rest and in response to exercise.

IL-6 plays a mechanistic role in conditions such as metabolic syndrome, chronic fatigue syndrome and clinical depression and also plays a major role in inflammatory and immune responses to exercise. The purpose of this study was to investigate the levels of resting and post exercise IL-6 when measured in venous plasma, saliva and capillary plasma. Five male and five females completed 2 separate exercise trials, both of which involved standardized exercise sessions on a cycle ergometer. Venous blood and saliva samples were taken immediately before and after Trial A, venous and capillary blood samples were taken immediately before and after Trial B. IL-6 values were obtained using a high-sensitivity enzyme-linked immunosorbent assay (ELISA). In Trial A venous plasma IL-6 increased significantly from 0.4±0.14pg/ml to 0.99±0.29pg/ml (P<0.01) while there was no increase in salivary IL-6. Venous plasma and salivary IL-6 responses were not correlated at rest, post exercise or when expressed as an exercise induced change. In Trial B venous and capillary plasma IL-6 increased significantly (venous: 0.22±0.18 to 0.74±0.28pg/ml (P⩽0.01); capillary: 0.37±0.22 to 1.08±0.30pg/ml (P<0.01). Venous and capillary plasma responses did not correlate at rest (r=0.59, P=0.07) but did correlate post exercise (r=0.79, P⩾0.001) and when expressed as an exercise induced change (r=0.71, P=0.02). Saliva does not appear to reflect systemic IL-6 responses, either at rest or in response to exercise. Conversely, capillary plasma responses are reflective of systemic IL-6 responses to exercise.

Challenging behaviour and sleep cycle disorder following brain injury: a preliminary response to agomelatine treatment.

BACKGROUND: Sleep disturbances are common after acquired brain injury. Sedatives can exacerbate behavioural disorders. OBJECTIVES: This study reports the case of a severely brain damaged man (TM) who developed a non-24 hour sleep cycle disorder that was effectively managed by the administration of a melatonin receptor agonist, agomelatine. METHOD: TM suffered significant brain damage as a result of a large subarachnoid haemorrhage of his right anterior cerebral artery complicated by midline shift and subsequent infarction of his left middle cerebral artery. In addition to challenging behaviour and cognitive impairment, TM presented with a recurrent disturbed sleep-wake pattern that significantly worsened his quality-of-life. He was diagnosed as suffering of non-24 hour sleep-wake disorder. Challenge was recorded using the Overt Aggression Scale Modified for Neuro-Rehabilitation (OASMNR). RESULTS: Typical hypnotics had no or ill effects. Agomelatine prescription (25 mg) led to significant OASMNR and sleep efficiency change with effects apparent at 1.5 years later. CONCLUSIONS: Administration of the melatonin receptor (MT1 and MT2) agonist agomelatine each night resulted in an immediate and sustained improvement on sleep and on indices of challenging behaviour.

Completing the circle: follow-up screening of STD patients in three clinics of the United States Indian Health Service.

We reviewed charts of newly diagnosed STD patients in three health facilities to determine the proportion who received follow-up STD screening. In a 12-month period, the three facilities had 140 STD cases. STD screening was not indicated for 50 (36%) patients. Among the 90 remaining STD patients, 29 (32%) were screened and 61 (68%) not screened. Among non-screened patients, 36% (22/61) were tested, but outside the time parameters allowed by the audit. The remaining 64% (39/61) received no screening at all, and represented clinical missed opportunities; in this group, nearly all (95%) had chlamydia but were not screened for HIV or syphilis. Linking chlamydia patients with a screen for HIV and syphilis using a clinical reminder in the facilities' electronic health record (EHR) or other tool, would eliminate 95% of the missed opportunities in this sample.

A combined analysis of 2 randomized clinical studies of tretinoin gel 0.05% for the treatment of acne.

Acne vulgaris is a widely prevalent skin disorder primarily treated with retinoids, which have been shown to cause skin irritation. This report describes the combined analysis of 2 similar phase 3 studies designed to evaluate the efficacy and safety of an aqueous gel formulation of tretinoin relative to its vehicle (both studies) and a marketed microsphere formulation of tretinoin (one study) for once-daily topical treatment of acne. Randomized participants 10 years and older with mild to moderate acne (N=1537) received tretinoin gel 0.05% (n=674), tretinoin gel microsphere 0.1% (n=376), or vehicle (n=487) once daily for 12 weeks. Tretinoin gel was more effective than vehicle in reducing inflammatory (P<.001) and noninflammatory (P<.001) lesion counts over 12 weeks. Treatment success rate (global severity score, 0 or 1) was significantly greater in the tretinoin gel 0.05% group compared with the vehicle group (P<.001). The efficacy rate of tretinoin gel 0.05% was approximately 12% less than tretinoin gel microsphere 0.1%. Adverse events (AEs) were generally mild to moderate and rarely resulted in participant discontinuation. Incidence of skin-related AEs in the tretinoin gel 0.05% group (31%) was significantly lower compared with the tretinoin gel microsphere 0.1% group (52%)(P<.001). Thus, tretinoin gel 0.05% applied once daily is a well-tolerated and effective therapy for acne vulgaris and is associated with a low incidence of skin-related AEs.

Perception and quality of life associated with the use of olopatadine 0.2% (Pataday) in patients with active allergic conjunctivitis.

This 28-d, open-label, multicenter, single-arm clinical study was designed to evaluate perceptions of olopatadine 0.2% in patients with active ocular allergic signs and symptoms. The study enrolled 330 patients, 5 to 94 y of age, who had previously used olopatadine 0.1% for active allergic conjunctivitis. Most patients were white (n=230; 70.1%) and female (n=239; 72.9%). Of all enrolled patients, 328 were evaluable for analysis. Throughout the study, patients instilled 1 drop of olopatadine 0.2% into each eye once daily; adverse events were documented and ocular evaluations were conducted to ensure patient safety. Direct evaluations of efficacy were not performed. On days 1 and 7, patients completed the Rhinoconjunctivitis Quality of Life Questionnaire, recorded their perceptions of olopatadine 0.1% (day 1) or 0.2% (day 7), and had their ocular allergies assessed globally. On each of the first 6 d of treatment, patients also completed a telephone-based perception questionnaire. On day 28, patients returned to the study center, reported their treatment perceptions, had their ocular allergies assessed, and exited the trial. Overall, patients had a positive perception of olopatadine 0.2%. Patients were more satisfied with olopatadine 0.2% than they remembered being with olopatadine 0.1% (289 vs 257 patients; 87.6% vs 77.8%; P<.05). The majority of the 48 patients who wore contact lenses (n=42; 88%) believed that they could wear their contacts as desired. Significant improvement was noted in all categories of the Rhinoconjunctivitis Quality of Life Questionnaire (P<.0001). No unexpected safety findings were reported. Patients perceived olopatadine 0.2% to be effective and well tolerated.

Testing models of thalamic dysfunction in schizophrenia using neuroimaging.

Neural models of schizophrenia have implicated the thalamus in deficits of early sensory processing and multimodal integration. We have reviewed the existing neuroimaging literature for evidence in support of models that propose abnormalities of thalamic relay nuclei, the mediodorsal thalamic nucleus, and large-scale cortico-thalamic networks. Thalamic volume reduction was found in some but not all studies. Studies of the early stages of schizophrenia suggest that thalamic volume reduction is present early in the course of the illness. Functional imaging studies have revealed task related abnormalities in several cortical and subcortical areas including the thalamus, suggesting a disruption of distributed thalamocortical networks. Chemical imaging studies have provided evidence for a loss of thalamic neuronal integrity in schizophrenia. There is, at present, inadequate data to support the hypothesis that schizophrenia is associated with abnormalities of sensory relay or association nuclei. There is evidence for a perturbation of cortico-thalamic networks, but further research is needed to elucidate the underlying mechanisms at the cellular and systems levels. The challenges ahead include better delineation of thalamic structure and function in vivo, the combination of genetic and imaging techniques to elucidate the genetic contributions to a thalamic phenotype of schizophrenia, and longitudinal studies of thalamic structure and function.

Effects of a new formulation of olopatadine ophthalmic solution on nasal symptoms relative to placebo in two studies involving subjects with allergic conjunctivitis or rhinoconjunctivitis.

BACKGROUND: A new formulation of olopatadine hydrochloride ophthalmic solution (olopatadine 0.2%) was evaluated in two separate, randomized, placebo-controlled, double-masked, hybrid environmental studies intended to determine efficacy and safety in subjects with histories of seasonal allergic conjunctivitis or rhinoconjunctivitis. DESIGN AND METHODS: In these 10- and 12-week trials (conducted April-August 2003 and July-December 2001, respectively), subjects assessed their ocular signs and symptoms. Additionally, subjects in the 10-week trial evaluated the frequency of their nasal symptoms while subjects in the 12-week trial evaluated both the frequency and severity of their nasal symptoms. The two trials had a combined enrollment of 500 subjects (217 males, 283 females) including 44 children aged 10-17 years; the combined population was 81.4% Caucasian, 9.2% Black, 2% Hispanic, and 7.4% other. Daily throughout these studies, either ragweed (fall study) or grass (spring study) pollen counts were obtained from each investigative center. Slope analyses were conducted on the nasal symptom assessments by pollen count. RESULTS: The nasal results from the two clinical trials are presented herein. In the fall study, relative to placebo, olopatadine 0.2% significantly reduced the frequency of pollen effects on sneezing (p = 0.0355) and itchy nose (p = 0.0032), and reduced the severity of pollen effects on sneezing (p = 0.0451), itchy nose (p = 0.0178), and runny nose (p = 0.0327). In the spring study, olopatadine 0.2% significantly reduced the frequency of pollen effects on sneezing (p = 0.0017) and runny nose (p = 0.0031) relative to placebo. In the fall trial, 2 subjects discontinued due to treatment-related adverse events (tachycardia and dry eye), while in the spring study, no subject discontinued due to a treatment-related adverse event. No subject in either study suffered a treatment-related serious adverse event. CONCLUSIONS: For the subjects enrolled in these studies, olopatadine 0.2% appeared to be safe, well-tolerated, and effective in significantly reducing the frequency and/or severity of some effects of pollen on nasal symptoms.

Clinical efficacy of olopatadine hydrochloride ophthalmic solution 0.2% compared with placebo in patients with allergic conjunctivitis or rhinoconjunctivitis: a randomized, double-masked environmental study.

BACKGROUND: Previous studies have suggested that olopatadine hydrochloride ophthalmic solution 0.2% administered once daily is effective for up to 24 hours after instillation and is well tolerated in adults and children aged > or =3 years. OBJECTIVE: The goal of this study was to evaluate the efficacy and safety profile of olopatadine 0.2% compared with placebo in patients with seasonal allergic conjunctivitis or rhinoconjunctivitis. METHODS: This was a 10-week, randomized, placebo-controlled, double-masked environmental study conducted during the spring allergy season (April-August) of 2003. Patients assessed their ocular signs and symptoms in terms of frequency (whole-unit scale from 0 to 5) and severity (half-unit scale from 0 to 4), and grass pollen counts were obtained daily for each investigative site. Responder analyses were conducted by pollen level (frequency based) and pollen period (severity based) to evaluate the clinical significance of differences in ocular itching and redness between treatment groups. RESULTS: Two hundred sixty patients (137 females, 123 males) were enrolled in the study, including 28 children aged between 11 and 17 years; the overall population was 74% white, 11% black, 4% Hispanic, and 11% other. The frequency-based responder analyses of ocular itching and redness showed that when grass pollen counts were high (>20 gr/m(3) air), a respective 21% and 14% of patients in the olopatadine 0.2% group assessed the frequency of ocular itching and redness as >2, compared with 47% and 31% of patients in the placebo group (P < 0.001 for ocular itching; P < 0.003 for redness). The results of the severity-based responder analyses by peak pollen period were consistent with those of the frequency-based analyses. Compared with placebo, olopatadine 0.2% was associated with significant reductions in calculated mean scores for ocular itching and redness by pollen level and by pollen period. No patient was discontinued from the study because of a treatment-related adverse event, and no patient experienced a treatment-related serious adverse event. CONCLUSION: In the patients studied, olopatadine 0.2% appeared to be effective and well tolerated when administered once daily for the treatment of the ocular signs and symptoms of allergic conjunctivitis or rhinoconjunctivitis.

Preclinical and clinical antiallergic effect of olopatadine 0.2% solution 24 hours after topical ocular administration.

Pharmacologic studies examined the potential of a solution containing olopatadine to maintain and extend antiallergic efficacy after single topical ocular drop administration over 24 hours. Results of these preclinical experiments conducted in guinea pigs indicated that olopatadine 0.2% (wt/vol) solution was significantly effective 24 hours after dosing. This concentration of olopatadine provided significantly more efficacy than Patanol (olopatadine 0.1%) 24 hours after administration while being as effective as Patanol (olopatadine 0.1%) 5 minutes after administration. Results from a human conjunctival allergen challenge trial in sensitive subjects confirmed clinical efficacy of olopatadine 0.2% solution over 24 hours. When individuals were challenged with antigen at onset, 16 and 24 hours after drug administration onto the eye, significant reductions were observed in the scores for active drug as compared with placebo for pruritus (77, 77, and 61%), conjunctival redness (35, 28, and 20%), and chemosis (53, 41, and 31%), respectively. These data suggest that topically applied olopatadine 0.2% solution will be an effective once-a-day therapy for allergic conjunctivitis.

A postmortem study of the mediodorsal nucleus of the thalamus in schizophrenia.

Four studies have reported that the mediodorsal nucleus of the thalamus (MD) is smaller and contains fewer neurons in schizophrenia. The MD is a key node in a circuit proposed to be dysfunctional in the disorder. However, one study did not find a MD volume loss in schizophrenia, and all the studies to date are relatively small. Given the importance of establishing unequivocally the presence of MD pathology, we have carried out a study of the volume and number of neurons in the left and right MD in 21 patients with schizophrenia and 27 healthy comparison subjects. We also measured the size of MD neurons, and estimated total thalamic volume. We found no difference in the volume of the MD, the number of MD neurons, or the size of MD neurons in either hemisphere in schizophrenia. Neither was total thalamic volume altered. There are no obvious methodological or clinical factors to explain our failure to replicate the finding of MD involvement in schizophrenia. Hence our negative observations, in the largest sample yet investigated, cast doubt on the robustness and/or the generalisability of MD neuropathology in schizophrenia.

The long-term effect of an innovative family physician curricular pathway on the specialty and location of graduates of the University of Washington.

PURPOSE: To report the specialty and rural/urban distribution a mean of 19 years after graduation for a cohort of students from a family physician curricular pathway. METHOD: Specialty and location information for medical students who had entered the University of Washington between 1968 and 1973 was obtained from the 1994 Physician Masterfile of the American Medical Association. RESULTS: Of the 239 family physician pathway graduates, 173 (72%) had intended family practice at graduation, and 136 (57%) were family physicians two decades later. The proportions of all graduates in family practice and of graduates serving rural Washington as family physicians had increased over that of a cohort of students who had entered the University of Washington prior to the introduction of the pathway curriculum. These proportions surpassed the goals set at the time the new curriculum was introduced. CONCLUSION: With early identification and support of students interested in family practice, an increased number entered the specialty and were still family physicians in mid-career.

The National Health Service Corps: rural physician service and retention.

BACKGROUND: The National Health Service Corps (NHSC) scholarship program is the most ambitious program in the United States designed to supply physicians to medically underserved areas. In addition to providing medical service to underserved populations, the NHSC promotes long-term retention of physicians in the areas to which they were initially assigned. This study uses existing secondary data to explore some of the issues involved in retention in rural areas. METHODS: The December 1991 American Medical Association (AMA) Masterfile was used to determine the practice location and specialty of the 2903 NHSC scholarship recipients who graduated from US medical schools from 1975 through 1983 and were initially assigned to nonmetropolitan counties. We used the AMA Masterfile to determine what percentage of the original cohort was still practicing in their initial county of assignment and the relation of original practice specialty and assignment period to long-term retention. RESULTS: Twenty percent of the physicians assigned to rural areas were still located in the county of their initial assignment, and an additional 20 percent were in some other rural location in 1991. Retention was highest for family physicians and lowest for scholarship recipients who had not completed residency training when they were first assigned. Retention rates were also higher for those with longer periods of obligated service. Substantial medical care service was provided to rural underserved communities through obligated and postobligation service. Nearly 20 percent of all students graduating from medical schools between 1975 and 1983 who are currently practicing in rural counties with small urbanized populations were initially NHSC assignees. CONCLUSIONS: Although most NHSC physicians did not remain in their initial rural practice locations, a substantial minority are still rural practitioners; those remaining account for a considerable proportion of all physicians in the most rural US counties. This study suggests that rural retention can be enhanced by selecting more assignees who were committed to and then completed family medicine residencies before assignment.