Construction of online catalog topologies using decision trees

Organization of a Web site is important to help users get the most out of the site. A good Web site should help visitors find the information they want easily. Visitors typically find information by searching for selected terms of interest or by following links from one Web page to another. The first approach is more useful if the visitor knows exactly what he is seeking, while the second approach is useful when the visitor has less of a preconceived notion about what he wants. The organization of a Web site is especially important in the latter case. Traditionally, Web site organization is done by hand. In this paper, we introduce the problem of automatic Web site construction and propose a solution for solving a major step of the problem based on decision tree algorithms. The solution is found to be useful in automatic construction of product catalogs.published_or_final_versio

TRPM channels are required for rhythmicity in the ultradian defecation rhythm of C. elegans.

BACKGROUND: Ultradian rhythms, rhythms with a period of less than 24 hours, are a widespread and fundamental aspect of life. The mechanisms underlying the control of such rhythms remain only partially understood. Defecation in C. elegans is a very tightly controlled rhythmic process. Underlying the defecation motor programme is an oscillator which functions in the intestinal cells of the animal. This mechanism includes periodic calcium release and subsequent intercellular calcium waves which in turn regulate the muscle contractions that make up the defecation motor programme. Here we investigate the role of TRPM cation channels in this process. RESULTS: We use RNA interference (RNAi) to perturb TRPM channel gene expression. We show that combined knock down of two of the TRPM encoding genes, gon-2 and gtl-1, results in an increase in the variability of the cycle but no change in the mean, in normal culture conditions. By altering the mean using environmental (temperature) and genetic approaches we show that this increase in variability is separable from changes in the mean. We show that gon-2 and gtl-1 interact with components of the calcium signalling machinery (itr-1 the C. elegans inositol 1,4,5-trisphosphate receptor) and with plasma membrane ion channels (flr-1 and kqt-3) which are known to regulate the defecation oscillator. Interactions with these genes result in changes to the mean period and variability. We also show that knocking down a putative transcription factor can suppress the increased variability caused by reduction of gon-2 and gtl-1 function. We also identify a previously unrecognised tendency of the defecation cycle to compensate for cycles with aberrant length by adjusting the length of the following cycle. CONCLUSION: Thus TRPM channels regulate the variability of the defecation oscillator in C. elegans. We conclude that the mean and the variability of the defecation oscillator are separable. Our results support the notion that there is a strong underlying pacemaker which is able to function independently of the observable defecation rhythm and is not perturbed by increases in the variability of the cycle. The interaction of gon-2 and gtl-1 with other components of the oscillator shows that TRPM channels play an important role in the oscillator machinery. Such a role may be through either regulation of cation levels or membrane properties or both. Specifically our results support previous proposals that gon-2 and gtl-1 regulate IP3 signalling and that kqt-3 may act by altering calcium influx. Our results provide novel insights into the properties of the defecation oscillator and thus to our understanding of ultradian rhythms.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Chemoselective reduction and oxidation of ketones in water through control of the electron transfer pathway

The selective synthesis of different products from the same starting materials in water, which is the most abundant solvent in nature, is a crucial issue as it maximizes the utilization of materials. Realizing such reactions for ketones is of considerable importance because numerous organic functionalities can be obtained via nucleophilic addition reactions. Herein, we report chemoselective reduction and oxidation reactions of 1,2-diketones in water, which initiates anionic electron transfer from the inorganic electride [Ca24Al28O64](4+)center dot 4e(-), through controlling the pathway of the electrons to substrates. The generation of different radical species for transient intermediates was the key process required to control the reaction selectivity, which was achieved by reacting the anionic electrons with either diketones or O-2, leading to the formation of ketyl dianion and superoxide radicals in the reduction and oxidation reactions, respectively. This methodology that utilizes electrides may provide an alternative to the pulse radiolysis of water in synthetic chemistry1441sciescopu

Gauged Flavor Group with Left-Right Symmetry

We construct an anomaly-free extension of the left-right symmetric model, where the maximal flavor group is gauged and anomaly cancellation is guaranteed by adding new vectorlike fermion states. We address the question of the lowest allowed flavor symmetry scale consistent with data. Because of the mechanism recently pointed out by Grinstein et al. tree-level flavor changing neutral currents turn out to play a very weak constraining role. The same occurs, in our model, for electroweak precision observables. The main constraint turns out to come from WR-mediated flavor changing neutral current box diagrams, primarily K - Kbar mixing. In the case where discrete parity symmetry is present at the TeV scale, this constraint implies lower bounds on the mass of vectorlike fermions and flavor bosons of 5 and 10 TeV respectively. However, these limits are weakened under the condition that only SU(2)_R x U(1)_{B-L} is restored at the TeV scale, but not parity. For example, assuming the SU(2) gauge couplings in the ratio gR/gL approx 0.7 allows the above limits to go down by half for both vectorlike fermions and flavor bosons. Our model provides a framework for accommodating neutrino masses and, in the parity symmetric case, provides a solution to the strong CP problem. The bound on the lepton flavor gauging scale is somewhat stronger, because of Big Bang Nucleosynthesis constraints. We argue, however, that the applicability of these constraints depends on the mechanism at work for the generation of neutrino masses.Comment: 1+23 pages, 1 table, 5 figures. v3: some more textual fixes (main change: discussion of Lepton Flavor Violating observables rephrased). Matches journal versio

Anti-Allergic Cromones Inhibit Histamine and Eicosanoid Release from Activated Human and Murine Mast Cells by Releasing Annexin A1

PMCID: PMC3601088This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

The Characteristics of Seebeck Coefficient in Silicon Nanowires Manufactured by CMOS Compatible Process

Silicon nanowires are patterned down to 30 nm using complementary metal-oxide-semiconductor (CMOS) compatible process. The electrical conductivities of n-/p-leg nanowires are extracted with the variation of width. Using this structure, Seebeck coefficients are measured. The obtained maximum Seebeck coefficient values are 122 μV/K for p-leg and −94 μV/K for n-leg. The maximum attainable power factor is 0.74 mW/m K2 at room temperature

Amyotrophic Lateral Sclerosis Is Associated with Hypolipidemia at the Presymptomatic Stage in Mice

OBJECTIVE: To demonstrate that hypolipidemia is a typical feature of the mouse model of amyotrophic lateral sclerosis (ALS) and to assess the association between hypolipidemia and disease stage, dietary intake, and sex. METHODS: We compared daily dietary intake, body weight, and serumlipid and glucose levels in ALS mice and wild-type controls at different stages of the disease. FINDINGS: Total cholesterol low-density lipoprotein (LDL) and LDL/high-density lipoprotein (HDL) ratio were significantly lower in ALS mice compared with controls. Subgroup analysis revealed that the incidence of hypolipidemia was significantly greater in male, but not female, ALS mice compared with control mice and that hypolipidemia was present at the presymptomatic stage of the disease. This hypolipidemia can be found without a decrease in the serum levels of other energy sources, such as glucose, in the presymptomatic stage. CONCLUSIONS: Hypolipidemia is present at the presymptomatic stage of the ALS mouse model in the absence of malnutrition, significant neuromuscular degeneration or regeneration, and respiratory difficulty. Our findings suggest that hypolipidemia might be associated with the pathomechanism of ALS and/or lipid-specific metabolism rather than simply an epiphenomenon of neuromuscular degeneration or energy imbalance

Prognostic parameters for recurrence of papillary thyroid microcarcinoma

<p>Abstract</p> <p>Background</p> <p>Papillary thyroid microcarcinoma (PTMC) is defined as a papillary thyroid carcinoma less than or equal to 1.0 cm in size. Independent prognostic factors for clinical recurrence of PTMC have not been clearly delineated.</p> <p>Methods</p> <p>Clinicopathological parameters predicting PTMC recurrence were determined by retrospective analysis of 307 patients.</p> <p>Results</p> <p>Of the 293 patients eligible for analysis, 14 (5%) had recurrence during a median follow-up time of 65 months. Recurrence was observed in 8 of 166 patients (0.5%) treated with total or near-total thyroidectomy; gender (P = 0.02) and presence of lateral cervical node metastases at initial surgery (P = 0.01) were associated with recurrence. Six of the 127 patients (0.5%) treated with hemi- or subtotal thyroidectomy experience recurrences, but no significant prognostic factor for recurrence was identified. Multivariate Cox-regression analysis showed that gender and cervical lymph node metastasis were significant variables</p> <p>Conclusion</p> <p>PTMC showed very diverse disease extent and could not be regarded as indolent, relatively benign disease based on the primary tumor size. The extent of surgery should be based on prognostic parameters, such as gender and lateral neck node metastasis, in patients with PTMC.</p

IVF for premature ovarian failure: first reported births using oocytes donated from a twin sister

BACKGROUND: Premature ovarian failure (POF) remains a clinically challenging entity because in vitro fertilisation (IVF) with donor oocytes is currently the only treatment known to be effective. METHODS: A 33 year-old nulligravid patient with a normal karyotype was diagnosed with POF; she had a history of failed fertility treatments and had an elevated serum FSH (42 mIU/ml). Oocytes donated by her dizygotic twin sister were used for IVF. The donor had already completed a successful pregnancy herself and subsequently produced a total of 10 oocytes after a combined FSH/LH superovulation regime. These eggs were fertilised with sperm from the recipient\u27s husband via intracytoplasmic injection and two fresh embryos were transferred to the recipient on day three. RESULTS: A healthy twin pregnancy resulted from IVF; two boys were delivered by caesarean section at 39 weeks\u27 gestation. Additionally, four embryos were cryopreserved for the recipient\u27s future use. The sister-donor achieved another natural pregnancy six months after oocyte retrieval, resulting in a healthy singleton delivery. CONCLUSION: POF is believed to affect approximately 1% of reproductive age females, and POF patients with a sister who can be an oocyte donor for IVF are rare. Most such IVF patients will conceive from treatment using oocytes from an anonymous oocyte donor. This is the first report of births following sister-donor oocyte IVF in Ireland. Indeed, while sister-donor IVF has been successfully undertaken by IVF units elsewhere, this is the only known case where oocyte donation involved twin sisters. As with all types of donor gamete therapy, pre-treatment counselling is important in the circumstance of sister oocyte donation