Sleep-disordered breathing (SDB) is among the most common diseases and includes a group of pathological conditions that form a severity continuum from primary snoring (PS) to obstructive sleep apnea ...(OSA). SDB presents a multifactorial etiology and in children, it is often linked to adenotonsillar hypertrophy, which may lead to an alteration of the breathing pattern. Therefore, several studies hinted at the existence of a correlation between SDB and the alteration of craniofacial growth. However, these studies concentrated on the most severe forms of SDB and little evidence still exists for the mildest form of SDB, namely PS. This preliminary study investigates the association between nasal airflow, measured through rhinomanometry, and cephalometric parameters in a sample of young children with PS.
A sample of 30 children with habitual snoring aged between 5 and 8 years was selected by a SDB validated questionnaire at the Pediatric Allergology and Immunology Center of "Sapienza" University of Rome, Italy. To assess the degree of nasal obstruction, all children underwent anterior active rhinomanometry while nocturnal pulse oximetry and polysomnography were used to characterize the SDB. Cephalometric analysis was used to evaluate relevant orthodontic parameters associated to the sagittal and vertical craniofacial development and to the position of the hyoid bone.
We found a statistically significant association between the Frankfurt mandibular angle (FMA), which measures the total facial vertical divergence, and the severity of the airflow's obstruction (p = 0.014).
The present study supports the association between the level of nasal obstruction in children with PS and the alteration of cephalometric parameters associated with the vertical craniofacial growth, thus placing the evaluation of craniofacial parameters in the growth period in a privileged position to determine an early diagnosis of a possible insurgence of sleep disorders.
This work focuses on the synthesis and characterization of a novel bioresorbable glass ceramic phosphate-based material (GC-ICEL). More specifically, its solubility in different aqueous media (water, ...Tris-HCl and acellular simulated body fluid) and the response of human stromal cells cultured on it were investigated. X-ray diffraction analysis showed the presence of two crystalline phases identified as Na2Mg(PO4)3 and Ca2P2O7 and dissolution tests highlighted a preferential dissolution of the Na2Mg(PO4)3 phase and of the residual amorphous phase in all the chosen media. Soaking tests in simulated body fluid showed precipitation of a hydroxyapatite layer, demonstrating the bioactivity of GC-ICEL, which is partially due to the reported bioactivity of Ca2P2O7. The effect of GC-ICEL on adhesion, proliferation and osteoblastic gene expression of human bone marrow-derived stromal cells was also studied. Combining molecular and biochemical analyses, it was found that bone marrow cell differentiation was stimulated over proliferation on GC-ICEL. Moreover, the expression of bone-related genes in cells cultured on GC-ICEL confirmed the bioactivity of this phosphate-based glass ceramic, which might have a stimulatory effect on osteogenesis.
A precision test of lepton flavour universality has been performed by measuring the ratio RK of kaon leptonic decay rates K+→e+ν and K+→μ+ν in a sample of 59 813 reconstructed K+→e+ν candidates with ...(8.71±0.24)% background contamination. The result RK=(2.487±0.013)×10−5 is in agreement with the Standard Model expectation.
Kisspeptin has been implicated in the ovulatory process of several species of spontaneous ovulators but in only one induced ovulator. In contrast, NGF in semen is the principal trigger of ovulation ...in other species of induced ovulators—camelids. We tested the hypotheses that kisspeptin induces luteinizing hormone (LH) secretion in llamas through a hypothalamic mechanism, and kisspeptin neurons are the target of NGF in its ovulation-inducing pathway. In Experiment 1, llamas were given either NGF, kisspeptin, or saline intravenously, and LH secretion and ovulation were compared among groups. All llamas treated with NGF (5/5) or kisspeptin (5/5) had an elevation of LH blood concentrations after treatment and ovulated, whereas none of the saline group did (0/5). In Experiment 2, llamas were either pretreated with a gonadotropin-releasing hormone (GnRH) receptor antagonist or saline and treated 2 h later with kisspeptin. Llamas pretreated with saline had elevated plasma LH concentrations and ovulated (6/6) whereas llamas pretreated with cetrorelix did not (0/6). In Experiment 3, we evaluated the hypothalamic kisspeptin-GnRH neuronal network by immunohistochemistry. Kisspeptin neurons were detected in the arcuate nucleus, the preoptic area, and the anterior hypothalamus, establishing synaptic contacts with GnRH neurons. We found no colocalization between kisspeptin and NGF receptors by double immunofluorescence. Functional and morphological findings support the concept that kisspeptin is a mediator of the LH secretory pathway in llamas; however, the role of kisspeptins in the NGF ovulation-inducing pathway in camelids remains unclear since NGF receptors were not detected in kisspeptin neurons in the hypothalamus. Summary sentence Kisspeptin induces LH secretion and ovulation in llamas.
Desde la década del setenta, el capitalismo se presenta cada vez más como una realidad sin alternativas. Esta, montada cual velo alrededor de su carácter real contradictorio, ha sido desglosada ...muchas veces por la izquierda para la imaginación de un mundo después del trabajo. En los últimos años, la aceleración producida por el desarrollo tecnológico, al mismo tiempo que configura nuevas formas de alienación, se manifiesta como la posibilidad de transición hacia un más allá del capitalismo. Pero, para poder aprovecharla, antes es necesario, como afirma Nick Srnicek, un diagnóstico crítico de la economía actual que tenga en cuenta su infraestructura fundamental: las plataformas.
Throughput Region of Finite-Buffered Networks Giaccone, P.; Leonardi, E.; Shah, D.
IEEE transactions on parallel and distributed systems,
02/2007, Letnik:
18, Številka:
2
Journal Article
Recenzirano
Most of the current communication networks, including the Internet, are packet switched networks. One of the main reasons behind the success of packet switched networks is the possibility of ...performance gain due to multiplexing of network bandwidth. The multiplexing gain crucially depends on the size of the buffers available at the nodes of the network to store packets at the congested links. However, most of the previous work assumes the availability of infinite buffer-size. In this paper, we study the effect of finite buffer-size on the performance of networks of interacting queues. In particular, we study the throughput of flow-controlled loss-less networks with finite buffers. The main result of this paper is the characterization of a dynamic scheduling policy that achieves the maximal throughput with a minimal finite buffer at the internal nodes of the network under memory-less (e.g., Bernoulli IID) exogenous arrival process. However, this ideal performance policy is rather complex and, hence, difficult to implement. This leads us to the design of a simpler and possibly implementable policy. We obtain a natural trade-off between throughput and buffer-size for such implementable policy. Finally, we apply our results to packet switches with buffered crossbar architecture
The objective of the present study was to compare the effect of a single versus multiple doses of a 10-amino acid fragment of human (hKp) or murine (mKp) kisspeptin on LH secretion and the fate of ...the dominant follicle. In all experiments, a new wave was induced (Day 0) by ultrasound-guided ablation of >5 mm follicles, a progesterone device (CIDR) was placed in the vagina, animals given prostaglandin F2α analog im on Day 3.5 and 4, and hKp or mKp treatment given on Day 6. The experimental design maintained growth and ovulatory potential of the dominant follicle for 12 days and allowed hypothesis testing during the low-progesterone period (plasma progesterone ≤1.8 ng/ml on Day 6) wherein spontaneous wave emergence and ovulation did not occur between Day 6 and Day 12. In Experiment 1, heifers (n = 10/group) were given single iv dose of 45 mg hKp, 45 mg mKp, or 2 ml normal saline (control). Post-treatment plasma LH concentrations from 15 to 90 min were higher (P < 0.01) in hKp group than in the mKp and control groups. Two heifers ovulated in hKp group versus none in other groups. In Experiment 2, heifers (n = 6/group) were given 45 mg hKp over a 2 h period divided into multiple iv doses treatments or 2 ml normal saline (control). Post-treatment plasma LH concentrations were higher (P < 0.01) in all hKp treatment groups than in the control group. The ovulation rate was higher (P = 0.06) after hKp treatments (11/18) than in the control group (0/6). In Experiment 3, heifers (n = 6/group) were given 45 mg mKp over a 2 h period divided into multiple iv doses treatments or a single iv dose of gonadorelin acetate (positive control). Plasma LH concentration was higher (P < 0.01) and the ovulation rate was greater (P = 0.01) in the GnRH group (5/6) than mKp groups (1/12). In summary, hKp was more effective to induce ovulation than mKp. Human kisspeptin-10 given over a 2 h period induced ovulations at a rate similar to that of GnRH treatment in heifers under a low plasma progesterone state.
•Single dose of human kisspeptin-10 increased plasma LH concentration more than the murine kisspeptin-10.•Multiple administration of human kisspeptin-10 was more effective than the murine sequence for inducing ovulation rate.•Multiple human kisspeptin-10 treatments induced ovulation and follicular wave emergence at rates comparable to that of GnRH.
Kisspeptin modulates GnRH secretion in mammals and peripheral administration of 10-amino acid fragment of kisspeptin (Kp10) induces LH release and ovulation in cattle. Experiments were done to ...determine if iv administration of kisspeptin will activate GnRH neurons (i.e., after crossing the blood-brain barrier) and if pre-treatment with a GnRH receptor blocker will alter kisspeptin-induced LH release (from gonadotrophs) and ovulation. In Experiment 1, cows (n = 3 per group) were given human-Kisspeptin10 (hKp10; 3 x 15 mg iv at 60-min intervals) or normal saline and euthanized 150 min after treatment was initiated. Every 20th free-floating section (50 μm thickness) from the preoptic area to hypothalamus was double immunostained to colocalize GnRH- (DAB) and activated neurons (cFOS; Nickel-DAB). Kisspeptin induced plasma LH release from 15 to 150 min (P = 0.01) but the proportion of activated GnRH neurons did not differ between groups (5.8% and 3.5%, respectively; P = 0.11). Immunogold electron microscopy detected close contacts between kisspeptin fibers and GnRH terminals in the median eminence. In Experiment 2, pubertal heifers (n = 5 per group) were treated with 1) hKp10 iv, 2) Cetrorelix (GnRH antagonist; im) + hKp10 iv or 3) saline on Day 6 of the follicular wave under low-progesterone condition. A rise in plasma LH concentration was detected from 15 to 240 min in the hKp10 group but not in cetrorelix or control group (P<0.001). Ovulations were detected only in the hKp10 group (4/5; P = 0.02). Cetrorelix treatment was associated with regression of the preovulatory dominant follicle and emergence of a new follicular wave 3.4±0.75 days after the treatment in all five heifers. Results support the hypothesis that the effect of peripheral kisspeptin is mediated downstream of GnRH synthesis and does not involve GnRH-independent LH release from gonadotrophs. Peripheral kisspeptin may release pre-synthesized GnRH from the nerve terminals in areas outside the blood-brain barrier.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The von Hippel–Lindau (VHL) tumor suppressor gene is a protein interaction hub, controlling numerous genes implicated in tumor progression. Here we focus on structural aspects of protein interactions ...for a list of 35 experimentally verified protein VHL (pVHL) interactors. Using structural information and computational analysis we have located three distinct interaction interfaces (A, B, and C). Interface B is the most versatile, recognizing a refined linear motif present in 17 otherwise non-related proteins. It has been possible to distinguish compatible and exclusive interactions by relating pVHL function to interaction interfaces and subcellular localization. A novel hypothesis is presented regarding the possible function of the N-terminus as an inhibitor of pVHL function.
The paper studies input-queued packet switches loaded with both unicast and multicast traffic. The packet switch architecture is assumed to comprise a switching fabric with multicast (and broadcast) ...capabilities, operating in a synchronous slotted fashion. Fixed-size data units, called cells, are transferred from each switch input to any set of outputs in one time slot, according to the decisions of the switch scheduler, that identifies at each time slot a set of nonconflicting cells, i.e., cells neither coming from the same input, nor directed to the same output. First, multicast traffic admissibility conditions are discussed, and a simple counterexample is presented, showing intrinsic performance losses of input-queued with respect to output-queued switch architectures. Second, the optimal scheduling discipline to transfer multicast packets from inputs to outputs is defined. This discipline is rather complex, requires a queuing architecture that probably is not implementable, and does not guarantee in-sequence delivery of data. However, from the definition of the optimal multicast scheduling discipline, the formal characterization of the sustainable multicast traffic region naturally follows. Then, several theorems showing intrinsic performance losses of input-queued with respect to output-queued switch architectures are proved. In particular, we prove that, when using per multicast flow FIFO queueing architectures, the internal speedup that guarantees 100% throughput under admissible traffic grows with the number of switch ports.
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