Search

New Jefferson Lab data are presented on the nuclear dependence of the inclusive cross section from (2)H, (3)He, (4)He, (9)Be and (12)C for 0.3 < x < 0.9, Q(2) approximately 3-6 GeV(2). These data represent the first measurement of the EMC effect for (3)He at large x and a significant improvement for (4)He. The data do not support previous A-dependent or density-dependent fits to the EMC effect and suggest that the nuclear dependence of the quark distributions may depend on the local nuclear environment.

In Ethiopia, like many developing countries, autopsy is rare unless conducted in the medico-legal arena, making vital statistics that include pathological diagnoses sparse. To determine the most common factors contributing to death among individuals who died from natural or injury-related events in Ethiopia 200 consecutive autopsies were conducted in 2006 at the Forensic Medico-legal Pathology Department, Menelik II Hospital, Addis Ababa, Ethiopia. The results describe significant pathological observations, putative cause of death, age distribution, and gender ratios. Eighty-one percent of the cases were male, and the mean age was 38.9 (+/-15.5 years). Fifty-two percent of the individuals died from natural causes, including infections, and 48% died from injury-related events. In the natural deaths group, as determined by gross examination at autopsy pulmonary complications were the most commonly reported cause of death, with suspected tuberculosis accounting for 12%. Tuberculosis (21, 8%) and liver disease (14, 5%) were the most common histopathological findings in the natural and injury-related causes groups, respectively. In the injury-related group, automobile accident was the most common cause of accidental death (80%), and homicide by beating was the most common cause of death in the intentional injury group (31%). These data provide valuable unbiased analyses of causes of death among individuals in Addis Ababa, Ethiopia.

Ariocarpus bravoanus is common in trade but critically endangered in its natural habitat. With the ultimate aim of developing a certification scheme to aid in the conservation of this species, we have isolated A. bravoanus microsatellites from a nonenriched library. Fifty-four sequences contained a microsatellite array, of which eight were polymorphic among 23 individuals, 20 from one population and three plants from trade., (© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.)

Echinocactus grusonii is common in trade but critically endangered in its natural habitat. With the ultimate aim of developing a certification scheme to aid in the conservation of this species, we have isolated E. grusonii microsatellites from a nonenriched library. Fifty-seven sequences contained a microsatellite array, of which 12 were polymorphic among 30 individuals from a single wild population. All 12 microsatellite primer pairs amplified product in one or more species in a screen of 27 other cactus species., (© 2007 The Authors.)

An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a 12C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring imaging Cherenkov detector were added to the hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed (Lambda)(12)B spectrum shows for the first time identifiable strength in the core-excited region between the ground-state s-wave Lambda peak and the 11 MeV p-wave Lambda peak.

The widespread use of atrazine (ATR) and its persistence in the environment have resulted in documented human exposure. Alterations in hypothalamic catecholamines have been suggested as the mechanistic basis of the toxicity of ATR to hormonal systems in females and the reproductive tract in males. Because multiple catecholamine systems are present in the brain, however, ATR could have far broader effects than are currently understood. Catecholaminergic systems such as the two major long-length dopaminergic tracts of the central nervous system play key roles in mediating a wide array of critical behavioral functions. In this study we examined the hypothesis that ATR would adversely affect these brain dopaminergic systems. Male rats chronically exposed to 5 or 10 mg/kg ATR in the diet for 6 months exhibited persistent hyperactivity and altered behavioral responsivity to amphetamine. Moreover, when measured 2 weeks after the end of exposure, the levels of various monoamines and the numbers of tyrosine hydroxylase-positive (TH+) and -negative (TH-) cells measured using unbiased stereology were reduced in both dopaminergic tracts. Acute exposures to 100 or 200 mg/kg ATR given intraperitoneally to evaluate potential mechanisms reduced both basal and potassium-evoked striatal dopamine release. Collectively, these studies demonstrate that ATR can produce neurotoxicity in dopaminergic systems that are critical to the mediation of movement as well as cognition and executive function. Therefore, ATR may be an environmental risk factor contributing to dopaminergic system disorders, underscoring the need for further investigation of its mechanism(s) of action and corresponding assessment of its associated human health risks.

Purpose: The hypotheses of this investigation were that endovascular radiation would reduce intimal hyperplasia in arteriovenous fistulas (AVFs) and that this reduction would be associated with decreased expression of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF)-A, and tumor necrosis factor (TNF)-alpha., Materials and Methods: Bilateral end jugular vein-to-side carotid artery fistulas were constructed in pigs. At 48 hours, one AVF was randomly selected for endovascular radiation with (192) Iridium. The contralateral fistula received no radiation and served as a control. Animals in group 1 (n = 7) received 14 Gy of radiation at a depth of 2 mm and tissue was harvested at 29 days; animals in group 2 received 7 Gy of radiation at a depth of 2 mm and tissue was harvested at 29 days (n = 8); and animals in group 3 received 7 Gy of radiation at a depth of 2 mm and tissue was harvested at 56 days (n = 8). The area and maximum thickness of intimal hyperplasia were then measured blindly. Immunohistochemical results for VEGF, PDGF-A, and TNFalpha were obtained and analyzed blindly by assigning a score of 0-3, with 0 indicating no staining and 3 indicating maximum staining., Results: Irradiation with 14 Gy caused severe fibrosis in the media of the vein, with thrombosis of three of seven AVFs. Compared with the control group, the group that underwent irradiation with 7 Gy had significantly reduced intimal area at 56 days (9.9 mm(2) +/- 4.9 vs 2.1 mm(2) +/- 1.1; P =.001). This reduction correlated with significant reduction in the expression of VEGF (score of 2.2 +/- 0.1 vs 1.2 +/- 0.2; P =.001) and TNFalpha (1.3 +/- 0.1 vs 0.9 +/- 0.1; P =.04)., Conclusion: Fourteen grays is an excessive radiation dose for veins, causing medial fibrosis and thrombosis of the AVF. Irradiation with 7 Gy effectively inhibited the formation of intimal hyperplasia in AVF. This inhibition correlated with decreased expression of VEGF and TNFalpha.

Surgical ablation for oncological disease of the lateral skull base can result in extensive defects, with exposed bone and dura. Inadequate coverage can result in meningitis, osteomyelitis, or delay in adjuvant therapy. Successful reconstruction requires well-vascularized soft tissue and often a large cutaneous component. This study evaluates the role of free tissue transfer in reconstruction of lateral skull base defects. This study is a retrospective review of all patients undergoing lateral skull base resection for oncological disease and immediate reconstruction from 1993 through 1997. There were 18 patients with a mean age of 57 years. The temporal bone was resected in 50% of patients. All defects were reconstructed with free tissue transfers from the following donor sites: rectus abdominis (N = 14), latissimus dorsi (N = 2), anterolateral thigh (N = 1), and lateral arm (N = 1). A cutaneous skin island was employed in all patients. Free flap survival was 100%. Flap-related complications occurred in 33% of patients but did not delay the onset of adjuvant therapy. Vein grafts were not required to lengthen the vascular pedicle. Two patients required split-thickness skin grafts because of inadequate size of the skin island. Four patients underwent flap revision for contour deformity a mean of 4 months postoperatively. Free tissue transfer is a highly reliable method of reconstructing lateral skull base defects in a single stage. Careful flap selection and design can minimize the need for skin and vein grafts. The rectus abdominis donor site is preferred because of its location, large skin island, and excellent vascular pedicle.

Relationships between symptom profile and clozapine response were studied. Symptom scores on the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms were subjected to principal component analysis (PCA) in a group of 66 treatment-resistant schizophrenic patients, 49 of whom were treated with clozapine. Factor scores were compared among responders, non-responders and partial responders. The PCA yielded a four-factor solution, with positive symptoms, negative symptoms, cognitive disorganization and behavioral disorganization components. Cognitive and behavioral disorganization syndrome scores showed significant differences across groups. Cognitive disorganization was higher in non-responders, while behavioral disorganization was higher in partial responders. The results support the possibility of using clinical profiles to predict therapeutic response to clozapine.

Tye IV tympanoplasty was performed on 72 patients having advanced suppurative disease of the middle ear and mastoid with total loss of the middle ear sound transmission system. The principal features of the method consist of a postauricular wide-field mastoidectomy, canalplasty, meatoplasty, Type IV tympanoplasty with cutaneous exteriorization of the footplate and mastoid obliteration. The method achieved a postoperative bone-air gap of 30 db or less in 59 percent of cases with a 15 percent incidence of recrudescence requiring some further surgery.