Central Counterparts Research Articles

MAC Protocol for Quality-Aware Real-Time Voice Delivery in Cognitive Radio-Enabled WSNs

We propose a quality-aware media access control (MAC) protocol for real-time voice delivery in cognitive radio- (CR-) enabled wireless sensor networks (WSNs). The temporal structure of the system model is addressed by using periodic timeslots in order to make more efficient use of the spectrum. In our proposed temporal structure, a bandwidth broker in such centralized CR networks (CCRNs) is selected as a central counterpart to synchronize with secondary users (SUs) and assign spectral resources to them. We develop an analytical model for SUs for the Call Admission Control (CAC) of voice traffic using the quality of service (QoS) requirements of delay bound and delay bound violation probability. Ours is an approach that provides reliable data transmission and reduces packet delay and packet delay jitter. In addition to the aforementioned packet-level performance metrics, we calculated a call-level performance metric, that is, the number of acceptable SUs, satisfying QoS requirements.

Isolating endosteal mesenchymal progenitors from rodent long bones.

Bone marrow mesenchymal stem cells (MSCs) are promising therapeutic tools for tissue repair and the treatment of a number of human diseases. As a result, there is substantial interest in characterizing and expanding these cells to uncover their therapeutic potential. For preclinical studies, mesenchymal progenitors, containing both MSCs and their proliferative progeny, are commonly isolated from the central region of rodent long bones. However, challenges exist in expanding these central mesenchymal progenitors in culture. We have recently identified another population of progenitors within rodent long bones that resides close to the bone surface, which we termed endosteal mesenchymal progenitors. These cells are more metabolically active and more responsive to external stimuli compared to central mesenchymal progenitors and therefore, they represent a biologically important target for MSC research. This chapter describes in detail a unique enzymatic digestion approach to isolate and culture endosteal mesenchymal progenitors as well as their central counterparts from rodent long bones.

Pożegnanie z monarchią habsburską

A Farewell to the Habsburg Monarchy Od autonomii do niepodleglości. Ksztaltowanie sie postaw narodowych i politycznych spoleczenstwa Galicji w warunkach Wielkiej Wojny 1914–1918 (Kielce 2012) by Jerzy Z. Pająk deals with the shaping of national awareness among the population of Galicia in 1914–1918, and pays particular attention to mutual relations between the Polish, Ukrainian, and Jewish communities and the course of their emancipation from the partitioning power. The national and political stances of the population of Galicia were also moulded by other important factors discussed by the author; an essential role was played by local Austrian authorities as well as their central counterparts in Vienna involved in decisions of key importance for the fate of Galicia. The political and national attitudes of the inhabitants of the Austrian partition area were also influenced by the Roman Catholic and Greek Catholic Churches. The author conducted extensive research in archives in Poland and Lviv. Much information about relations between the Poles and the authorities of the Habsburg monarchy as well as Ukrainian and Jewish neighbours is to be found in material omitted by Pająk and contained in the Austrian State Archives in Vienna (Allgemeines Verwaltungsarchiv, Kriegsarchiv, Haus-, Hofund Staatsarchiv). These sources refer to to numerous central institutions of the Austro-Hungarian monarchy, such as the imperial cabinet, the Austrian government, assorted ministries, the supreme military command, and the Intelligence and Counter-Intelligence services.

Relative Frequency of Peripheral Odontogenic Tumors and Comparison with Central Counterpart: a 20-Year Evaluation

Relative Frequency of Peripheral Odontogenic Tumors and Comparison with Central Counterpart: a 20-Year Evaluation

Ecological correlates in Brazilian Amazonian anurans: implications for conservation

The objective of the present study is to identify the ecological characteristics of Amazonian frogs that would make them candidates for endangered species status, and to quantify correlations between body size and geographic distribution. The study included 180 species for which information was available on life history characteristics, including reproductive mode, aquatic larval development, primary larval habitat and adult microhabitat, and activity period. Species with aquatic development were classified in eight ecological groups based on a cluster analysis. Twenty-eight of the aquatic-developing species share a stream-based larval development stage with groups of endangered or vulnerable species from Australia and Central America. The Amazonian species have geographic ranges around five times larger than their Australian and Central American counterparts. The median clutch size and geographic range in aquatic-developing anuran species were 20 percent and 3.3 percent greater, respectively, than those of terrestrial-developing species. For both aquatic- and terrestrial-developing species, body size was positively associated with clutch size. Body size was also correlated with geographic range in aquatic-developing, but not in terrestrial species. Restricted geographic ranges and a lack of populations in protected areas were recorded in both groups. Most of these species occur in the southwestern Brazilian Amazon, which not only has poor coverage of protected areas, but is becoming increasingly threatened by ongoing economic development. The systematic monitoring of the region’s anurans and the creation of new conservation units should thus be of the highest priority.

Mesenchymal progenitors residing close to the bone surface are functionally distinct from those in the central bone marrow

Long bone is an anatomically complicated tissue with trabecular-rich metaphyses at two ends and cortical-rich diaphysis at the center. The traditional flushing method isolates only mesenchymal progenitor cells from the central region of long bones and these cells are distant from the bone surface. We propose that mesenchymal progenitors residing in endosteal bone marrow that is close to the sites of bone formation, such as trabecular bone and endosteum, behave differently from those in the central bone marrow. In this report, we separately isolated endosteal bone marrow using a unique enzymatic digestion approach and demonstrated that it contained a much higher frequency of mesenchymal progenitors than the central bone marrow. Endosteal mesenchymal progenitors express common mesenchymal stem cell markers and are capable of multi-lineage differentiation. However, we found that mesenchymal progenitors isolated from different anatomical regions of the marrow did exhibit important functional differences. Compared with their central marrow counterparts, endosteal mesenchymal progenitors have superior proliferative ability with reduced expression of cell cycle inhibitors. They showed greater immunosuppressive activity in culture and in a mouse model of inflammatory bowel disease. Aging is a major contributing factor for trabecular bone loss. We found that old mice have a dramatically decreased number of endosteal mesenchymal progenitors compared with young mice. Parathyroid hormone (PTH) treatment potently stimulates bone formation. A single PTH injection greatly increased the number of endosteal mesenchymal progenitors, particularly those located at the metaphyseal bone, but had no effect on their central counterparts. In summary, endosteal mesenchymal progenitors are more metabolically active and relevant to physiological bone formation than central mesenchymal progenitors. Hence, they represent a biologically important target for future mesenchymal stem cell studies.

Declining Genetic Diversity and Increasing Genetic Isolation toward the Range Periphery ofStipa pennata, a Eurasian Feather Grass

A common assumption in ecology and evolutionary biology is that genetic diversity declines and differentiation increases toward the edge of a species’ geographic range, where populations tend to be smaller and more isolated. We tested these predictions in a characteristic Eurasian steppe plant, Stipa pennata, by inspecting 230 AFLP bands in 26 populations (345 individuals) along a 3300-km longitudinal gradient from the range core, in Russia, to the range periphery, in central Europe. Overall, our study species showed low genetic diversity within populations (mean proportion of polymorphic ) and moderately high genetic differentiation among them (mean ). As predicted, genetic diversity declined significantly from the range core to the periphery but was not correlated with population size. Pairwise genetic differentiation was significantly higher among peripheral populations than central populations but did not show a pronounced relationship with geographic distance. Our results indicate that peripheral populations may experience higher genetic drift and lower gene flow than their central counterparts, possibly because of smaller population sizes, spatial isolation, and a more complex landscape structure. In addition, historic range fluctuations and the mixed breeding system could have enhanced the observed patterns in our study species.

Correlated Markov Quantum Walks

We consider the discrete time unitary dynamics given by a quantum walk on $\Z^d$ performed by a particle with internal degree of freedom, called coin state, according to the following iterated rule: a unitary update of the coin state takes place, followed by a shift on the lattice, conditioned on the coin state of the particle. We study the large time behavior of the quantum mechanical probability distribution of the position observable in $\Z^d$ for random updates of the coin states of the following form. The random sequences of unitary updates are given by a site dependent function of a Markov chain in time, with the following properties: on each site, they share the same stationnary Markovian distribution and, for each fixed time, they form a deterministic periodic pattern on the lattice. We prove a Feynman-Kac formula to express the characteristic function of the averaged distribution over the randomness at time $n$ in terms of the nth power of an operator $M$. By analyzing the spectrum of $M$, we show that this distribution posesses a drift proportional to the time and its centered counterpart displays a diffusive behavior with a diffusion matrix we compute. Moderate and large deviations principles are also proven to hold for the averaged distribution and the limit of the suitably rescaled corresponding characteristic function is shown to satisfy a diffusion equation. An example of random updates for which the analysis of the distribution can be performed without averaging is worked out. The random distribution displays a deterministic drift proportional to time and its centered counterpart gives rise to a random diffusion matrix whose law we compute. We complete the picture by presenting an uncorrelated example.

Dissecting the relative contribution of central versus peripheral opioid analgesia: Are the analgesic and adverse effects of opioids inseparable?

Dissecting the relative contribution of central versus peripheral opioid analgesia: Are the analgesic and adverse effects of opioids inseparable?

Stimulation of Category-Selective Brain Areas Modulates ERP to Their Preferred Categories

Neural selectivity to specific object categories has been demonstrated in extrastriate cortex with both functional MRI [1-3] and event-related potential (ERP) [4, 5]. Here we tested for a causal relationship between the activation of category-selective areas and ERP to their preferred categories. Electroencephalogram (EEG) was recorded while participants observed faces and headless bodies. Concurrently with EEG recording, we delivered two pulses of transcranial magnetic stimulation (TMS) over the right occipital face area (OFA) or extrastriate body area (EBA) at 60 and 100 ms after stimulus onset. Results showed a clear dissociation between the stimulated site and the stimulus category on ERP modulation: stimulation of the OFA significantly increased the N1 amplitude to faces but not to bodies, whereas stimulation of the EBA significantly increased the N1 amplitude to bodies but not to faces. These findings provide the first evidence for a specific and causal link between activity in category-selective networks and scalp-recorded ERP to their preferred categories. This result also demonstrates that the face and body N1 reflects several nonoverlapping neural sources, rather than changes in face-selective mechanisms alone. Lastly, because early stimulation (60-100 ms) affected selectivity of a later ERP component (150-200 ms), the results could imply a feed-forward connection between occipital and temporal category-selective areas.

Random Time-Dependent Quantum Walks

We consider the discrete time unitary dynamics given by a quantum walk on the lattice $\Z^d$ performed by a quantum particle with internal degree of freedom, called coin state, according to the following iterated rule: a unitary update of the coin state takes place, followed by a shift on the lattice, conditioned on the coin state of the particle. We study the large time behavior of the quantum mechanical probability distribution of the position observable in $\Z^d$ when the sequence of unitary updates is given by an i.i.d. sequence of random matrices. When averaged over the randomness, this distribution is shown to display a drift proportional to the time and its centered counterpart is shown to display a diffusive behavior with a diffusion matrix we compute. A moderate deviation principle is also proven to hold for the averaged distribution and the limit of the suitably rescaled corresponding characteristic function is shown to satisfy a diffusion equation. A generalization to unitary updates distributed according to a Markov process is also provided. An example of i.i.d. random updates for which the analysis of the distribution can be performed without averaging is worked out. The distribution also displays a deterministic drift proportional to time and its centered counterpart gives rise to a random diffusion matrix whose law we compute. A large deviation principle is shown to hold for this example. We finally show that, in general, the expectation of the random diffusion matrix equals the diffusion matrix of the averaged distribution.

Efficiency and productivity of hospitals in Vietnam

The purpose of this paper is to examine the relative efficiency and productivity of hospitals during the health reform process. Data envelopment analyses method (DEA) with the input-oriented variable-returns-to-scale model was used to calculate efficiency scores. Malmquist total factor productivity index approach was then employed to calculate productivity of hospitals. Data of 101 hospitals was extracted from databases of the Ministry of Health, Vietnam from the years 1998 to 2006. There was evidence of improvement in overall technical efficiency from 65 per cent in 1998 to 76 per cent in 2006. Hospitals' productivity progressed around 1.4 per cent per year, which was mainly due to the technical efficiency improvement. Furthermore, provincial hospitals were more technically efficient than their central counterparts and hospitals located in different regions performed differently. The paper provides an insight in the performance of Vietnamese public hospitals that has been rarely examined before and contributes to the existing literature of hospital performance in developing countries

Opioid peptides in peripheral pain control.

Opioids have a long history of therapeutic use as a remedy for various pain states ranging from mild acute nociceptive pain to unbearable chronic advanced or end-stage disease pain. Analgesia produced by classical opioids is mediated extensively by binding to opioid receptors located in the brain or the spinal cord. Nevertheless, opioid receptors are also expressed outside the CNS in the periphery and may become valuable assets in eliciting analgesia devoid of shortcomings typical for the activation of their central counterparts. The discovery of endogenous opioid peptides that participate in the formation, transmission, modulation and perception of pain signals offers numerous opportunities for the development of new analgesics. Novel peptidic opioid receptor analogs, which show limited access through the blood brain barrier may support pain therapy requiring prolonged use of opioid drugs.

Peripheral odontogenic fibroma: A case report and review

Odontogenic tumors mainly occur as intraosseous growths but sometimes may present in a peripheral location on the gingiva where they are referred to as peripheral odontogenic tumors (POTs) which are a rare entity, the most common of them being the peripheral odontogenic fibroma that is an otherwise uncommon, slowly growing, benign odontogenic neoplasm of the periodontal soft tissues. In fact, peripheral odontogenic fibroma is the only POT that is more frequent than its central counterpart. Although considered to be with a potential to recur after excision, the actual recurrence rate is not known due to paucity of literature. This paper presents a case report along with review of the available literature and reinforces the importance of patient follow-up in addition to radiographic and histological examination of seemingly innocuous gingival exophytic lesions.

Regional Anesthesia

Regional Anesthesia

Effects of Changes in Public Policy on Efficiency and Productivity of General Hospitals in Vietnam

The health sector reform programme which began in Vietnam in 1989 in order to improve the efficiency of the health system has altered the way in which Vietnamese hospitals operate. The programme put the spotlight on input savings. This study aims to examine the relative efficiency of hospitals during the health reform process and assess - by looking at the relative efficiency of hospitals - the effects of the regulatory changes. The study employs the DEA two-stage approach referring to data from 101 general public hospitals over the period 1998-2006. The study revealed that there was evidence of improvement in the productivity of Vietnamese hospitals over the period 1998-2006, with a progress in total factor productivity of 1.4% per year. Furthermore, the differences in hospital efficiency can be attributed to both the regulatory changes and hospital-specific characteristics. The user fees and autonomy measures were found to increase technical efficiency. Provincial hospitals were revealed to be more technically efficient than their central counterparts and hospitals located in the North East, South East and Mekong River Delta regions performed better that hospitals from other regions.

Peripheral ameloblastic fibroma of the maxilla: report of a case and review of the literature

Peripheral odontogenic lesions are considered to be rare within the classification of odontogenic tumors. Also referred to as extraosseous or soft tissue odontogenic tumors, peripheral odontogenic tumors share the same histopathologic characteristics of their central or intraosseous counterparts. Ameloblastic fibroma is a rare odontogenic tumor that arises from both odontogenic epithelium and connective tissue. Only 2 cases of peripheral ameloblastic fibroma have been reported in the English-language literature, one of which did not show the classic features of an ameloblastic fibroma. In this report, we describe a rare case of a peripheral ameloblastic fibroma in the maxilla of a 3-year-old girl.

Resolution of the identity atomic orbital Laplace transformed second order Møller–Plesset theory for nonconducting periodic systems

An improvement in performance of the atomic orbital Laplace transformed second-order Møller-Plesset (AO-LT-MP2) method for periodic systems is reported using the resolution of identity (RI) technique. Transformation of the two-electron integrals constitutes the main computational bottleneck of the AO-LT-MP2 method. A substitution of regular four-center integrals by their three center counterparts in the RI approximation naturally reduces the computational cost of the integral transformation step. The RI divergence problem in the presence of periodic boundary conditions is solved in our implementation by restricting the fitting domain. Accuracy and computational efficiency of the RI-AO-LT-MP2 approach are assessed on a set of one-dimensional test systems: trans-polyacetylene and anti-transoid polymethineimine.

Density functional study of the electronic and vibrational properties of TiOCl

We present the phonon spectrum of TiOCl computed using hybrid density functional theory DFT .A complete analysis of the spectrum is performed for the space group Pmmn high-symmetry phase and the space group P21 /m low-symmetry phase, which is the symmetry of the spin-Peierls phase. We show that the nonlocal correlations present in the hybrid DFT approach are important for understanding the electron-lattice interactions in TiOCl. The computed frequencies compare well with those observed in Raman and infrared spectroscopy experiments, and we identify the origin of an anomalous phonon observed in Raman spectroscopy. The relationship between relevant zone boundary phonons in the high-symmetry phase and the zone center counterparts in the P21 /m symmetry allow us to speculate about the origin of the spin-Peierls phonon.

Preservation of nipple-areola complex in breast cancer – a clinicopathological assessment

Skin-sparing mastectomy (SSM) with immediate breast reconstruction (IBR), which traditionally includes the nipple-areola complex (NAC), is the modern way of improving the cosmetic and aesthetic outcome of advanced breast cancer surgery. However, with nipple and areola lacking, it fails to simulate the original breast. This study is directed at exploring the possibility of NAC preservation in selected mastectomy patients. A retrospective analysis of the breast specimens of 219 consecutive mastectomy patients was performed after categorising the tumour characteristics on the basis of their TNM staging. The relationship of malignant involvement of the NAC with positive regional lymph nodes (pN), tumour size (T), site, stage and skin involvement by the breast tumour was noted and analysed. Chi-square analysis was performed for different characteristics vis-à-vis NAC involvement. Two-sided lists, wherever possible, had been performed at the 5% level of significance and P values were evaluated. The total frequency of malignant involvement of NAC was 44 (20%) out of 219. The frequency of NAC involvement in stage I and II tumours was found to be 9.38% compared to stage III tumours where it was 30%. The NAC was involved in 4 (2.5%) of 160 patients with peripheral tumours compared with 40 (68%) of 59 patients with tumours located centrally. Only 2 (1.5%) of 130 peripheral tumours bigger than 5 cm had malignant NAC involvement while the number in their central counterparts was much bigger (59%). Not a single breast cancer patient with skin involvement in the peripheral quadrants had any nipple-areola involvement. NAC can be preserved in patients having stage I, II and III diseases with peripheral tumours less than 5 cm in size, irrespective of the nodal status and skin involvement.