Complete sequence of the bithorax complex of Drosophila

The bithorax complex (BX-C) of Drosophila, one of two complexes that act as master regulators of the body plan of the fly, is included within a sequence of 338,234 bp (SEQ89E). This paper presents the strategy used in sequencing SEQ89E and an analysis of its open reading frames. The BX-C sequence (BXCALL) contains 314,895 bp obtained by deletion of putative genes that are located at each end of SEQ89E and appear to be functionally unrelated to the BX-C. Only 1.4% of BXCALL codes for the three homeodomain-containing proteins of the complex. Principal findings include a putative ABD-A protein (ABD-AII) larger than a previously known ABD-A protein and a putative glucose transporter-like gene (1521 bp) located at or near the bithoraxoid (bxd), infra-abdominal-2 (iab-2) boundary on the opposite strand relative to that of the homeobox-containing genes.     

Molecular dynamics studies of AChBP with nicotine and carbamylcholine: the role of water in the binding pocket

The acetylcholine-binding protein (AChBP) is homologous to the ligand-binding domain of the nicotinic acetylcholine receptor (nAChR) and other members of the Cys-loop family of neurotransmitter receptors. The high-resolution X-ray structures of AChBP mean it has been used as a model from which to understand agonist and antagonist binding to nAChRs. We present here a molecular dynamics (MD) study of AChBP with nicotine and carbamylcholine bound. Our results suggest that the ligand imposes rigidity on the binding pocket residues. The simulations also suggest that the protein undergoes breathing motions with respect to the five-fold axis, a motion that has been postulated to be related to gating in the nAChR. We analyzed the behaviour of the water molecules in and around the binding site and found that they occupied five distinct sites within the binding pocket. Water occupied these sites in the absence of ligand, but the presence of ligand increased the probability that a water molecule would be found in these sites. Finally, we demonstrate how the positions of these waters might be used in the design of new ligands by comparing the positions of these sites with other recent structures.     

Relation of low-severity violence to women's health

OBJECTIVE: To determine if women who experience low-severity violence differ in numbers of physical symptoms, psychological distress, or substance abuse from women who have never been abused and from women who experience high-severity violence. DESIGN: Cross-sectional, self-administered, anonymous survey. SETTING: Four community-based, primary care, internal medicine practices. PATIENTS: Survey respondents were 1,931 women aged 18 years or older. SURVEY DESIGN: Survey included questions on violence; a checklist of 22 physical symptoms; the Symptom Checklist-22 (SCL-22) to measure depression, anxiety, somatization, and self-esteem; CAGE questions for alcohol use; and questions about past medical history. Low-severity violence patients had been "pushed or grabbed" or had someone "threaten to hurt them or someone they love" in the year prior to presentation. High-severity violence patients had been hit, slapped, kicked, burned, choked, or threatened or hurt with a weapon. MAIN RESULTS: Of the 1,931 women, 47 met criteria for current low-severity violence without prior abuse, and 79 met criteria for current high-severity violence without prior abuse, and 1,257 had never experienced violence. The remaining patients reported either childhood violence or past adult abuse. When adjusted for socioeconomic characteristics, the number of physical symptoms increased with increasing severity of violence (4.3 for no violence, 5.3 for low-severity violence, 6.4 for high-severity violence, p < .0001). Psychological distress also increased with increasing severity of violence (mean total SCL22 scores 32.6 for no violence, 35.7 for low-severity violence, 39.5 for high-severity violence, p < .0001). Women with any current violence were more likely to have a history of substance abuse (prevalence ratio [PR] 1.8 for low-severity, 1.9 for high-severity violence) and to have a substance-abusing partner (PR 2.4 for both violence groups). CONCLUSIONS: In this study, even low-severity violence was associated with physical and psychological health problems in women. The data suggest a dose-response relation between the severity of violence and the degree of physical and psychological distress.     

Brass intraocular foreign body: early intervention and combined surgical approach

The rapid development of suppurative reaction in response to a copper-containing intraocular foreign body disposes the eye to a poor prognosis. An intraocular brass foreign body case involving cornea, iris, lens, vitreous and retina was satisfactorily managed by early foreign body removal and corneal transplantation followed by scleral buckling for retinal detachment. Early intervention is advocated as alternative management with expectation of improvement in the prognosis for recovery of useful visual function.     

Turbulence near a sandbar island in the lower Missouri River

River turbulence is spatially variable due to interactions between morphology of rivers and physical mechanics of flowing water. Understanding the variation of turbulence in rivers is important for characterizing transport processes of soluble and particulate materials in these systems. We present an exploratory effort to understand ecologically relevant flow patterns using measurements of mean flow and turbulence in a highly engineered river channel around an island in the lower Missouri River. Specifically, the profiles of mean river velocities were investigated to examine the logarithmic relation and associated parameters, including shear velocity and bed roughness. Turbulence intensity and Reynolds shear stress were compared with classic open-channel profiles and previously reported river data in the hydraulics literature. With the capability of pulse-to-pulse coherent Doppler velocity profiling in high spatial resolution, we estimated the profiles of turbulence dissipation rate using resolved one-dimensional velocity spectra. These measurement data allow us to examine the validity of turbulence production-dissipation balance and the classic open-channel profiles of turbulence statistics, including turbulence intensity, Reynolds shear stress, dissipation rate, and eddy viscosity. The field data show a strong variation of turbulence profiles in close vicinity of the river island. In shallow water depths close to the island, turbulence is substantially enhanced in comparison with classic open-channel profiles. Such turbulence enhancement is likely attributed to non-uniformity of the flow structures.