On the Oberwolfach problem with two similar length cycles

For all in greater than or equal to 3, the Oberwolfach problem is solved for the case where the 2-factors consist of two cycles of lengths in and m + 1, and for the case where the 2-factors consist of two cycles of lengths m and m + 2.

Derivation of the probability distribution function for the local density of states of a disordered quantum wire via the replica trick and supersymmetry

We consider the statistical properties of the local density of states of a one-dimensional Dirac equation in the presence of various types of disorder with Gaussian white-noise distribution. It is shown how either the replica trick or supersymmetry can be used to calculate exactly all the moments of the local density of states.' Careful attention is paid to how the results change if the local density of states is averaged over atomic length scales. For both the replica trick and supersymmetry the problem is reduced to finding the ground state of a zero-dimensional Hamiltonian which is written solely in terms of a pair of coupled spins which are elements of u(1, 1). This ground state is explicitly found for the particular case of the Dirac equation corresponding to an infinite metallic quantum wire with a single conduction channel. The calculated moments of the local density of states agree with those found previously by Al'tshuler and Prigodin [Sov. Phys. JETP 68 (1989) 198] using a technique based on recursion relations for Feynman diagrams. (C) 2001 Elsevier Science B.V. All rights reserved.

Murine ventricular L-type Ca2+ current is enhanced by zinterol via beta(1)-adrenoceptors, and is reduced in TG4 mice overexpressing the human beta(2)-adrenoceptor

1 The functional coupling of B-2-adrenoceptors (beta (2)-ARs) to murine L-type Ca2+ current (I-Ca(L)) was investigated with two different approaches. The beta (2)-AR signalling cascade was activated either with the beta (2)-AR selective agonist zinterol (myocytes from wild-type mice), or by spontaneously active, unoccupied beta (2)-ARs (myocytes from TG4 mice with 435 fold overexpression of human beta (2)-ARs). Ca2+ and Ba2+ currents were recorded in the whole-cell and cell-attached configuration of the patch- clamp technique, respectively. 2 Zinterol (10 muM) significantly increased I-Ca(L) amplitude of wild-type myocytes by 19+/-5%, and this effect was markedly enhanced after inactivation of Gi-proteins with pertussis-toxin (PTX; 76+/-13% increase). However, the effect of zinterol was entirely mediated by the beta (1)-AR subtype, since it was blocked by the beta (1)-AR selective antagonist CGP 20712A (300 nM). The beta (2)-AR selective antagonist ICI 118,551 (50 nM) did not affect the response of I-Ca(L) to zinterol. 3 In myocytes with beta (2)-AR overexpression I-Ca(L) was not stimulated by the activated signalling cascade. On the contrary, I-Ca(L) was lower in TG4 myocytes and a significant reduction of single-channel activity was identified as a reason for the lower whole-cell I-Ca(L). The beta (2)-AR inverse agonist ICI 118,551 did not further decrease I-Ca(L). PTX-treatment increased current amplitude to values found in control myocytes. 4 In conclusion, there is no evidence for beta (2)-AR mediated increases of I-Ca(L) in wild-type mouse ventricular myocytes. Inactivation of Gi-proteins does not unmask beta (2)-AR responses to zinterol, but augments beta (1)-AR mediated increases of I-Ca(L). In the mouse model of beta (2)-AR overexpression I-Ca(L) is reduced due to tonic activation of Gi-proteins.

Parathyroid hormone (1-34): A major advance in the treatment of osteoporosis?

Osteoporosis is a major public health problem for older women and men. Parathyroid hormone (PTH) (1-34), which produces similar biological activity to the parent hormone, was tested in postmenopausal women with prior vertebral fractures. In 18 months, PTH (1-34) caused a dramatic 65% decrease in the risk of new vertebral fractures with a 10% increase in bone mineral density with few side effects. PTH (1-34) represents an exciting new therapy for this high risk group.

Woodstoves uncovered: a paediatric problem

Objectives: To document and describe the effects of woodstove burns in children. To identify how these accidents occur so that a prevention strategy can be devised. Design, Patients and Setting: Retrospective departmental database and case note review of all children with woodstove burns seen at the Burns Unit of a Tertiary Referral Children's Hospital between January 1997 and September 2001. Main outcome measures: Number and ages of children burned: circumstances of the accidents; injuries-sustained, treatment-required and long-term sequelae. Results. Eleven children, median age 1.0 year, sustained burns, usually to the hands, of varying thickness. Two children required skin grafting and five required scar therapy. Seven children intentionally placed their hands onto the Outside of the stove. In all children, burns occurred despite adult supervision Conclusions: Woodstoves area cause of burns in children. These injuries are associated with significant morbidity and financial costs. Through public education, woodstove burns can easily be prevented utilising simple safety measures. (C) 2002 Elsevier Science Ltd and ISBI All rights reserved.

Automatic construction of explicit R matrices for the one-parameter families of irreducible typical highest weight (0(m)vertical bar alpha(n)) representations of U-q[gl(m vertical bar n)]

We detail the automatic construction of R matrices corresponding to (the tensor products of) the (O-m\alpha(n)) families of highest-weight representations of the quantum superalgebras Uq[gl(m\n)]. These representations are irreducible, contain a free complex parameter a, and are 2(mn)-dimensional. Our R matrices are actually (sparse) rank 4 tensors, containing a total of 2(4mn) components, each of which is in general an algebraic expression in the two complex variables q and a. Although the constructions are straightforward, we describe them in full here, to fill a perceived gap in the literature. As the algorithms are generally impracticable for manual calculation, we have implemented the entire process in MATHEMATICA; illustrating our results with U-q [gl(3\1)]. (C) 2002 Published by Elsevier Science B.V.

Mechanistic aspects of HIV-1 reverse transcription initiation

During reverse transcription, the positive-strand HIV-1 RNA genome is converted into a double-stranded DNA copy which can be permanently integrated into the host cell genome. Recent analyses show that HIV-1 reverse transcription is a highly regulated process. The initiation reaction can be distinguished from a subsequent elongation reaction carried out by a reverse transcription complex composed of (at least) heterodimeric reverse transcriptase, cellular tRNA(lys3) and HIV-1 genomic RNA sequences. In addition, viral factors including Tat, Nef, Vif, Vpr, IN and NCp7, cellular proteins, and TAR RNA and other RNA stem-loop structures appear to influence this complex and contribute to the efficiency of the initiation reaction. As viral resistance to many antiretroviral compounds is a continuing problem, understanding the ways in which these factors influence the reverse transcription complex will likely lead to novel antiretroviral strategies. Copyright (C) 2001 John Wiley Sons, Ltd.

The Phox Homology (PX) domain-dependent, 3-phosphoinositide-mediated association of sorting nexin-1 with an early sorting endosomal compartment is required for its ability to regulate epidermal growth factor receptor degradation

Recent studies have shown that phox homology (PX) domains act as phosphoinositide-binding motifs. The majority of PX domains studied show binding to phosphatidylinositol 3-monophosphate (Ptdlns(3)P), an association that allows the host protein to localize to membranes of the endocytic pathway. One issue, however, is whether PX domains may have alternative phosphoinositide binding specificities that could target their host protein to distinct subcellular compartments or allow their allosteric regulation by phosphoinositides other than PtdIns(3)P. It has been reported that the PX domain of sorting nexin 1 (SNX1) specifically binds phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P-3) (Zhong, Q., Lazar, C. S., Tronchere, H., Sato, T., Meerloo, T., Yeo, M., Songyang, Z., Emr, S. D., and Gill, G. N. (2002) Proc. Natl. Acad. Sci. U. S. A. 99,6767-6772). In the present study, we have shown that whereas SNX1 binds PtdIns(3,4,5)P-3 in protein:lipid overlay assays, in liposomes-based assays, binding is observed to PtdIns(3)P and phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P-2) but not to PtdIns(3,4,5)P-3. To address the significance of PtdIns(3,4,5)P-3 binding, we examined the subcellular localization of SNX1 under conditions in which plasma membrane PtdIns(3,4,5)P-3 levels were significantly elevated. Under these conditions, we failed to observe association of SNX1 with this membrane. However, consistent with the binding to PtdIns(3)P and PtdIns(3,5)P-2 being of more physiological significance was the observation that the association of SNX1 with an early endosomal compartment was dependent on a 3-phosphoinositide-binding PX domain and the presence of PtdIns(3)P on this compartment. Finally, we somal association of SNX1 is important for its ability to regulate the targeting of internalized epidermal growth factor receptor for lysosomal degradation.

Locomotion at-1.0 degrees C: burst swimming performance of five species of Antarctic fish

We investigated the burst swimming performance of five species of Antarctic fish at -1.0degreesC. The species studied belonged to the suborder, Notothenioidei, and from the families, Nototheniidae and Bathydraconidae. Swimming performance of the fish was assessed over the initial 300 ms of a startle response using surgically attached miniature accelerometers. Escape responses in all fish consisted of a C-type fast start; consisting of an initial pronounced bending of the body into a C-shape, followed by one or more complete tail-beats and an un-powered glide. We found significant differences in the swimming performance of the five species of fish examined, with average maximum swimming velocities (U-max) ranging from 0.91 to 1.39 m s(-1) and maximum accelerations (A(max)) ranging from 10.6 to 15.6 m s(-2). The cryopelagic species, Pagothenia borchgrevinki, produced the fastest escape response, reaching a U-max and A(max) of 1.39 m s(-1) and 15.6 m s(-2), respectively. We also compared the body shapes of each fish species with their measures of maximum burst performance. The dragonfish, Gymnodraco acuticeps, from the family Bathdraconidae, did not conform to the pattern observed for the other four fish species belonging to the family Nototheniidae. However, we found a negative relationship between buoyancy of the fish species and burst swimming performance. (C) 2002 Elsevier Science Ltd. All rights reserved.

Factorizations of the complete graph into C-5-factors and 1-factors

In this paper, we show that K-10n can be factored into alpha C-5-factors and beta 1-factors for all non-negative integers alpha and beta satisfying 2alpha + beta = 10(n) - 1.

Link invariants associated with gauge equivalent solutions of the Yang-Baxter equation: The one-parameter family of minimal typical representations of Uq[gl(2|1)]

In this paper we investigate the construction of state models for link invariants using representations of the braid group obtained from various gauge choices for a solution of the trigonometric Yang-Baxter equation. Our results show that it is possible to obtain invariants of regular isotopy (as defined by Kauffman) which may not be ambient isotopic. We illustrate our results with explicit computations using solutions of the trigonometric Yang-Baxter equation associated with the one-parameter family of minimal typical representations of the quantum superalgebra U-q,[gl(2/1)]. We have implemented MATHEMATICA code to evaluate the invariants for all prime knots up to 10 crossings.

Managing urinary incontinence across the lifespan

In the 1996 baseline surveys of the Australian Longitudinal Study of Women's Health (ALSWH), 36.1% of mid-age women (45-50) and 35% of older women (70-75) reported leaking urine. This study aimed to investigate (a) the range of self-management strategies used to deal with urinary incontinence (UI); (b) the reasons why many women who report leaking urine do not seek help for UI; and (c) the types of health professionals consulted and treatment provided, and perceptions of satisfaction with these, among a sample of women in each age group who reported leaking urine often' at baseline. Five hundred participants were randomly selected from women in each of the mid-age and older cohorts of the ALSWH who had reported leaking urine often in a previous survey. Details about UI (frequency, severity, and situations), self-management behaviors and help-seeking for UI, types of health professional consulted, recommended treatment for the problem, and satisfaction with the service provided by health care professionals and the outcomes of recommended treatments were sought through a self-report mailed follow-up survey. Most respondents had leaked urine in the last month (94% and 91% of mid-age and older women, respectively), and 72.2% and 73. 1% of mid-aged and older women, respectively, had sought help or advice about their UI. In both age groups, the likelihood of having sought help significantly increased with severity of incontinence. The most common reasons for not seeking help were that the women felt they could manage the problem themselves or they did not consider it to be a problem.. Many women in both cohorts had employed avoidance techniques in an attempt to prevent leaking urine, including reducing their liquid consumption, going to the toilet just in case, and rushing to the toilet the minute they felt the need to. Strategies are needed to inform women who experience UI of more effective management techniques and the possible health risks associated with commonly used avoidance behaviors. There may be a need to better publicize existing incontinence services and improve access to these services for women of all ages.

A global health problem caused by arsenic from natural sources

Arsenic is a carcinogen to both humans and animals. Arsenicals have been associated with cancers of the skin, lung, and bladder. Clinical manifestations of chronic arsenic poisoning include non-cancer end point of hyper- and hypo-pigmentation, keratosis, hypertension, cardiovascular diseases and diabetes. Epidemiological evidence indicates that arsenic concentration exceeding 50 mug l(-1) in the drinking water is not public health protective. The current WHO recommended guideline value for arsenic in drinking water is 10 mug l(-1), whereas many developing countries are still having a value of 50 mug 1(-1). It has been estimated that tens of millions of people are. at risk exposing to excessive levels of arsenic from both contaminated water and arsenic-bearing coal from natural sources. The global health implication and possible intervention strategies were also discussed in this review article. (C) 2003 Elsevier Ltd. All rights reserved.

Unraveling the barriers to reconceptualization of the problem in chronic pain: The actual and perceived ability of patients and health professionals to understand the neurophysiology

To identify why reconceptualization of the problem is difficult in chronic pain, this study aimed to evaluate whether (1) health professionals and patients can understand currently accurate information about the neurophysiology of pain and (2) health professionals accurately estimate the ability of patients to understand the neurophysiology of pain. Knowledge tests were completed by 276 patients with chronic pain and 288 professionals either before (untrained) or after (trained) education about the neurophysiology of pain. Professionals estimated typical patient performance on the test. Untrained participants performed poorly (mean +/- standard deviation, 55% +/- 19% and 29% +/- 12% for professionals and patients, respectively), compared to their trained counterparts (78% +/- 21% and 61% +/- 19%, respectively). The estimated patient score (46% +/- 18%) was less than the actual patient score (P < .005). The results suggest that professionals and patients can understand the neurophysiology of pain but professionals underestimate patients' ability to understand. The implications are that (1) a poor knowledge of currently accurate information about pain and (2) the underestimation of patients' ability to understand currently accurate information about pain represent barriers to reconceptualization of the problem in chronic pain within the clinical and lay arenas. (C) 2003 by the American Pain Society.