Measuring Latency Variation in the Internet

We analyse two complementary datasets to quantify the latency variation experienced by internet end-users: (i) a large-scale active measurement dataset (from the Measurement Lab Network Diagnostic Tool) which shed light on long-term trends and regional differences; and (ii) passive measurement data from an access aggregation link which is used to analyse the edge links closest to the user. The analysis shows that variation in latency is both common and of significant magnitude, with two thirds of samples exceeding 100\,ms of variation. The variation is seen within single connections as well as between connections to the same client. The distribution of experienced latency variation is heavy-tailed, with the most affected clients seeing an order of magnitude larger variation than the least affected. In addition, there are large differences between regions, both within and between continents. Despite consistent improvements in throughput, most regions show no reduction in latency variation over time, and in one region it even increases. We examine load-induced queueing latency as a possible cause for the variation in latency and find that both datasets readily exhibit symptoms of queueing latency correlated with network load. Additionally, when this queueing latency does occur, it is of significant magnitude, more than 200\,ms in the median. This indicates that load-induced queueing contributes significantly to the overall latency variation.

Quality improvement within nonprofit social service providers

As a relatively new phenomenon in 2009, Swedish nonprofit social service providers proposed quality improvement as a way to reduce mistakes, use resources more effectively and meet the needs and expectations of clients in a better way. Although similar experiences have been studied in health care, the transfer of quality improvement to nonprofit social services gives a possibility for more knowledge on what enables, and constrains, systematic quality improvement in this specific context. This thesis is based on five years of supporting quality improvement in the Swedish nonprofit welfare sector. Specifically, it builds knowledge on which active mechanisms and enabling or constraining structures exist for nonprofit social service quality improvement. By studying quality improvement projects that have been conducted in the development program Forum for Values, critical cases and broad overviews are found valuable. These cases have resulted in four papers on quality improvement in nonprofit social services. The papers include: critical cases from a nursing home for elderly and a daycare for disabled children (Paper I); a critical case from a sheltered housing (Paper II); an overview of performance measurements in 127 quality improvement projects (Paper III); and an analytical model of how improvement policy and practice are bridged by intermediaries (Paper IV). In this thesis, enabled or constrained events and activities related to Deming's system of profound knowledge are identified from the papers and elaborated upon. As a basis for transforming practice into continuous improvement, profound knowledge includes the four knowledge domains: appreciation of a system, theory of knowledge, understanding of variation and psychology of change. From a realist perspective, the identified events are seen as enabled or constrained by mechanisms and underlying regularities, or structures, in the context of nonprofit social services. The emerging mechanisms found in this thesis are: describing and reflecting upon project relations; forming and testing a theory of action; collecting and displaying measurable results over time; and engaging and participating in a development program. The structures that enable these mechanisms are: connecting projects to shared values such as client needs; local ownership of what should be measured; and translating quality improvement into a single practice. Constraining structures identified are: a lack of generalizable scientific knowledge and inappropriate or missing infrastructure for measurements. Reflecting upon the emergent structures of nonprofit social services, the role of political macro structures, reflective practice, competence in statistical methods and areas of expertise becomes important. From this discussion and the findings some hypotheses for future work can be formulated. First, the identified mechanisms and structures form a framework that helps explain why intended actions of quality improvement occur or not. This frameworkcan be part of formulating a program theory of quality improvement in nonprofit social services. With this theory, quality improvement can be evaluated, reflected upon and further developed in future interventions. Second,new quality improvement interventions can be reproduced more regularly by active work with known enablers and constraints from this program theory. This means that long-lasting interventions can be performed and studied in a second generation of improvement efforts. Third, if organizations integrate quality improvement as a part of their everyday practice they also develop context-specific knowledge about their services. This context-specific knowledge can be adopted and further developed through dedicated management and understanding of variation. Thus, if enabling structures are invoked and constraining structures handled, systematic quality improvement could be one way to integrate generalizable scientific knowledge as part of an evidence-creating practice.

Impacto de la dinámica oceanográfica en la variación de azufre inorgánico en sedimentos de la Bahía de Paracas

Las condiciones oceanográficas y geoquímicas asociadas al azufre inorgánico fueron estudiadas en la bahía de Paracas para determinar su impacto en los procesos de sulfato-reducción, el intercambio de sulfuro de hidrógeno en la interfaz agua-sedimento y su movilización hacia la fracción precipitada. Se establecieron tres estaciones de muestreo al interior de la bahía entre abril y junio de 2015. La variación espacio-temporal de las especies de azufre inorgánico disuelto (H2S y SO4-2) y precipitado (Acid Volatile Sulfide AVS y Chromium-Reducible Sulfur CRS) se analizaron en relación a los factores ambientales: velocidad de vientos, oxígeno disuelto, temperatura, pH e indicadores de materia orgánica fresca (Cl-a) y de preservación de materia orgánica (COT y NT), así como azufre total (ST). A partir de los análisis de correlación cruzada, se infiere que en las estaciones más profundas hay una mayor correlación entre el oxígeno disuelto y la temperatura que en la estación somera, la correlación de estas variables con la velocidad de viento no fue significativa (p>0.05). Las aguas de fondo en la bahía muestran alternancia entre condiciones hipóxicas (<1,43 mL/L) y micróxicas (<0.10 mL/L) durante otoño con períodos prolongados y con máximas concentraciones de H2S (4,966.76 uM) en los primeros 20 cm del sedimento. El análisis de componentes principales sugiere condiciones más favorables para la sulfato reducción en abril y una mayor oxigenación en junio, a pesar de esto hay una tendencia de incremento de AVS y CRS hacia junio, posiblemente como una respuesta en desfase de las condiciones iniciales, ocasionando una mayor precipitación de monosulfuros de hierro y pirita hacia junio. A pesar de esta precipitación significativa de azufreexisten importantes flujos difusivos de H2S (en promedio de 574.76 μmol.m².d-1), colocando a la bahía de Paracas bajo un escenario de fuente de H2S, que podría alcanzar una condición más severa (2824.94 μmol.m².d-1) durante un evento de aguas blancas.

Lack of geographic variation in Y-chromosomal introns of red deer (Cervus elaphus)

Intra-specific Y-chromosomal sequence variation is useful for analysing the male contribution to a species’ spatial genetic structure. In red deer (Cervus elaphus) this is especially relevant, because geographic dispersal and game translocations occur mainly through the males. However, Y-chromosomal markers for wild organisms are scarce and frequently non-polymorphic within species. We assessed the intra-specific variation of two Y-chromosomal introns in red deer, one in the DBY (or DDX3Y) gene and the other in the UBE1Y gene. The introns were amplified using previously published exonic primers and directly sequenced in individuals of five red deer subspecies from across Eurasia. However, no nucleotide polymorphism was observed, which rebuts the usefulness of these introns for studies of red deer phylogeography and on illegal transport of red deer within this region. Male-based phylogeographic studies should thus be focused on other Y-chromosomal markers for this species.

Comparison of sequence variants in the PDK4 and COX4I2 genes between racing and cutting lines of quarter horses and associations with the speed index.

Different selection objectives within the Quarter Horse breed led to the formation of groups with distinct skills, including the racing and cutting lines. With a smaller population size in Brazil, but of great economic representativeness, the racing line is characterized by animals that can reach high speeds over short distances and within a short period of time. The cutting line is destined for functional tests, exploring skills such as agility and obedience. Although the athletic performance of horses is likely to be influenced by a large number of genes, few genetic variants have so far been related to this trait and this was done exclusively in Thoroughbreds, including the g.38973231G>A singlenucleotide polymorphism in the PDK4 gene and the g.22684390C>T single-nucleotide polymorphism in the COX4I2 gene. The results of the present study demonstrate the presence of polymorphic PDK4 and COX4I2 genes in Quarter Horses. The analysis of 296 racing animals and 68 cutting animals revealed significant differences in allele and genotype frequencies between the two lines. The same was not observed when these frequencies were compared between extreme racing performance phenotypes. There were also no significant associations between alleles of the two polymorphisms and the speed index. These results suggest that the alleles of the PDK4 and COX4I2 genes, which are related to better racecourse performance in Thoroughbreds, are probably associated with beneficial adaptations in aerobic metabolism and therefore play secondary roles in sprint racing performance in Quarter Horses, which is mainly anaerobic.

Computational resources for structural and metagenomic characterization of functions in bacteria and bacterial communities. Antimicrobial resistance, pathways for xenobiotic degradation and relationship between gut microbiome and ageing.

Prokaryotic organisms are one of the most successful forms of life, they are present in all known ecosystems. The deluge diversity of bacteria reflects their ability to colonise every environment. Also, human beings host trillions of microorganisms in their body districts, including skin, mucosae, and gut. This symbiosis is active for all other terrestrial and marine animals, as well as plants. With the term holobiont we refer, with a single word, to the systems including both the host and its symbiotic microbial species. The coevolution of bacteria within their ecological niches reflects the adaptation of both host and guest species, and it is shaped by complex interactions that are pivotal for determining the host state. Nowadays, thanks to the current sequencing technologies, Next Generation Sequencing, we have unprecedented tools for investigating the bacterial life by studying the prokaryotic genome sequences. NGS revolution has been sustained by the advancements in computational performance, in terms of speed, storage capacity, algorithm development and hardware costs decreasing following the Moore’s Law. Bioinformaticians and computational biologists design and implement ad hoc tools able to analyse high-throughput data and extract valuable biological information. Metagenomics requires the integration of life and computational sciences and it is uncovering the deluge diversity of the bacterial world. The present thesis work focuses mainly on the analysis of prokaryotic genomes under different aspects. Being supervised by two groups at the University of Bologna, the Biocomputing group and the group of Microbial Ecology of Health, I investigated three different topics: i) antimicrobial resistance, particularly with respect to missense point mutations involved in the resistant phenotype, ii) bacterial mechanisms involved in xenobiotic degradation via the computational analysis of metagenomic samples, and iii) the variation of the human gut microbiota through ageing, in elderly and longevous individuals.

[gait Speed, Grip Strength And Self-rated Health Among The Elderly: Data From The Fibra Campinas Network, São Paulo, Brazil].

The article seeks to investigate patterns of performance and relationships between grip strength, gait speed and self-rated health, and investigate the relationships between them, considering the variables of gender, age and family income. This was conducted in a probabilistic sample of community-dwelling elderly aged 65 and over, members of a population study on frailty. A total of 689 elderly people without cognitive deficit suggestive of dementia underwent tests of gait speed and grip strength. Comparisons between groups were based on low, medium and high speed and strength. Self-related health was assessed using a 5-point scale. The males and the younger elderly individuals scored significantly higher on grip strength and gait speed than the female and oldest did; the richest scored higher than the poorest on grip strength and gait speed; females and men aged over 80 had weaker grip strength and lower gait speed; slow gait speed and low income arose as risk factors for a worse health evaluation. Lower muscular strength affects the self-rated assessment of health because it results in a reduction in functional capacity, especially in the presence of poverty and a lack of compensatory factors.

Ecosystem Engineering Effects On Species Diversity Across Ecosystems: A Meta-analysis.

Ecosystem engineering is increasingly recognized as a relevant ecological driver of diversity and community composition. Although engineering impacts on the biota can vary from negative to positive, and from trivial to enormous, patterns and causes of variation in the magnitude of engineering effects across ecosystems and engineer types remain largely unknown. To elucidate the above patterns, we conducted a meta-analysis of 122 studies which explored effects of animal ecosystem engineers on species richness of other organisms in the community. The analysis revealed that the overall effect of ecosystem engineers on diversity is positive and corresponds to a 25% increase in species richness, indicating that ecosystem engineering is a facilitative process globally. Engineering effects were stronger in the tropics than at higher latitudes, likely because new or modified habitats provided by engineers in the tropics may help minimize competition and predation pressures on resident species. Within aquatic environments, engineering impacts were stronger in marine ecosystems (rocky shores) than in streams. In terrestrial ecosystems, engineers displayed stronger positive effects in arid environments (e.g. deserts). Ecosystem engineers that create new habitats or microhabitats had stronger effects than those that modify habitats or cause bioturbation. Invertebrate engineers and those with lower engineering persistence (<1 year) affected species richness more than vertebrate engineers which persisted for >1 year. Invertebrate species richness was particularly responsive to engineering impacts. This study is the first attempt to build an integrative framework of engineering effects on species diversity; it highlights the importance of considering latitude, habitat, engineering functional group, taxon and persistence of their effects in future theoretical and empirical studies.

Factors Associated With Reporting Of Abuse Against Children And Adolescents By Nurses Within Primary Health Care.

to analyze the factors associated with the underreporting on the part of nurses within Primary Health Care of abuse against children and adolescents. cross-sectional study with 616 nurses. A questionnaire addressed socio-demographic data, profession, instrumentation and knowledge on the topic, identification and reporting of abuse cases. Bivariate and multivariate logistic regression was used. female nurses, aged between 21 and 32 years old, not married, with five or more years since graduation, with graduate studies, and working for five or more years in PHC predominated. The final regression model showed that factors such as working for five or more years, having a reporting form within the PHC unit, and believing that reporting within Primary Health Care is an advantage, facilitate reporting. the study's results may, in addition to sensitizing nurses, support management professionals in establishing strategies intended to produce compliance with reporting as a legal device that ensures the rights of children and adolescents.

Interplay Of Weak Interactions In The Atom-by-atom Condensation Of Xenon Within Quantum Boxes.

Condensation processes are of key importance in nature and play a fundamental role in chemistry and physics. Owing to size effects at the nanoscale, it is conceptually desired to experimentally probe the dependence of condensate structure on the number of constituents one by one. Here we present an approach to study a condensation process atom-by-atom with the scanning tunnelling microscope, which provides a direct real-space access with atomic precision to the aggregates formed in atomically defined 'quantum boxes'. Our analysis reveals the subtle interplay of competing directional and nondirectional interactions in the emergence of structure and provides unprecedented input for the structural comparison with quantum mechanical models. This approach focuses on-but is not limited to-the model case of xenon condensation and goes significantly beyond the well-established statistical size analysis of clusters in atomic or molecular beams by mass spectrometry.

Artificial Gait In Complete Spinal Cord Injured Subjects: How To Assess Clinical Performance.

Objective Adapt the 6 minutes walking test (6MWT) to artificial gait in complete spinal cord injured (SCI) patients aided by neuromuscular electrical stimulation. Method Nine male individuals with paraplegia (AIS A) participated in this study. Lesion levels varied between T4 and T12 and time post injured from 4 to 13 years. Patients performed 6MWT 1 and 6MWT 2. They used neuromuscular electrical stimulation, and were aided by a walker. The differences between two 6MWT were assessed by using a paired t test. Multiple r-squared was also calculated. Results The 6MWT 1 and 6MWT 2 were not statistically different for heart rate, distance, mean speed and blood pressure. Multiple r-squared (r2 = 0.96) explained 96% of the variation in the distance walked. Conclusion The use of 6MWT in artificial gait towards assessing exercise walking capacity is reproducible and easy to apply. It can be used to assess SCI artificial gait clinical performance.

Weight Variation In Users Of Depot-medroxyprogesterone Acetate, The Levonorgestrel-releasing Intrauterine System And A Copper Intrauterine Device For Up To Ten Years Of Use.

Data on record regarding weight variation in depot-medroxyprogesterone acetate (DMPA) and levonorgestrel-releasing intrauterine system (LNG-IUS) users are controversial. To date, no studies have yet evaluated weight variation in DMPA and LNG-IUS users in up to ten years of use compared to non-hormonal contraceptive users. A retrospective study analysed weight variations in 2138 women using uninterruptedly DMPA (150 mg intramuscularly, three-monthly; n = 714), the LNG-IUS (n = 701) or a copper-intrauterine device (Cu-IUD; n = 723). At the end of the first year of use, there was a mean weight increase of 1.3 kg, 0.7 kg and 0.2 kg among the DMPA-, LNG-IUS- and Cu-IUD users, respectively, compared to weight at baseline (p < 0.0001). After ten years of use, the mean weight had risen by 6.6 kg, 4.0 and 4.9 kg among the DMPA-, LNG-IUS- and Cu-IUD users, respectively. DMPA-users had gained more weight than LNG-IUS- (p = 0.0197) and than Cu-IUD users (p = 0.0294), with the latter two groups not differing significantly from each other in this respect (p = 0.5532). Users of hormonal and non-hormonal contraceptive methods gained a significant amount of weight over the years. DMPA users gained more weight over the treatment period of up to ten years than women fitted with either a LNG-IUS or a Cu-IUD.

Investigation Of Genetic Factors Underlying Typical Orofacial Clefts: Mutational Screening And Copy Number Variation.

Typical orofacial clefts (OFCs) comprise cleft lip, cleft palate and cleft lip and palate. The complex etiology has been postulated to involve chromosome rearrangements, gene mutations and environmental factors. A group of genes including IRF6, FOXE1, GLI2, MSX2, SKI, SATB2, MSX1 and FGF has been implicated in the etiology of OFCs. Recently, the role of the copy number variations (CNVs) has been studied in genetic defects and diseases. CNVs act by modifying gene expression, disrupting gene sequence or altering gene dosage. The aims of this study were to screen the above-mentioned genes and to investigate CNVs in patients with OFCs. The sample was composed of 23 unrelated individuals who were grouped according to phenotype (associated with other anomalies or isolated) and familial recurrence. New sequence variants in GLI2, MSX1 and FGF8 were detected in patients, but not in their parents, as well as in 200 control chromosomes, indicating that these were rare variants. CNV screening identified new genes that can influence OFC pathogenesis, particularly highlighting TCEB3 and KIF7, that could be further analyzed. The findings of the present study suggest that the mechanism underlying CNV associated with sequence variants may play a role in the etiology of OFC.

Variation of the anal resting pressure induced by postexpiratory apnea effort in patients with constipation

CONTEXT: Intestinal constipation - a common symptom among the general population - is more frequent in women. It may be secondary to an improper diet or organic or functional disturbances, such as dyskinesia of the pelvic floor. This is basically characterized by the absence of relaxation or paradoxical contraction of the pelvic floor and anal sphincter during evacuation. OBJECTIVE: To analyze, by manometric data, the anal pressure variation at rest, during evacuation effort by using the Valsalva maneuver and forced post-expiratory apnea in subjects with secondary constipation. METHODS: Twenty-one patients (19 females - 90.4%) with a mean age of 47.5 years old (23-72) were studied. The diagnosis was performed using anorectal manometry, with a catheter containing eight channels disposed at the axial axis, measuring the proximal (1) and distal (2) portions of the anal orifice. The elevation of the pressure values in relation to the resting with the evacuation effort was present in all patients. The Agachan score was used for clinical evaluation of constipation. The variables studied were: mean anal pressure of the anal orifice for 20 seconds at rest, the effort of evacuation using Valsalva maneuver and the effort of evacuation during apnea after forced expiration, as well as the area under the curve of the manometric tracing at moments Valsalva and apnea. RESULTS: The analysis of the mean values of the anal pressure variation at rest evidenced difference between proximal and distal channels (P = 0.007), independent of the moment and tendency to differ during moments Valsalva and apnea (P = 0.06). The mean of values of the area under the manometric tracing curve showed differences between moments Valsalva and apnea (P = 0.0008), either at the proximal portion or at the distal portion of the anal orifice. CONCLUSION: The effort of evacuation associated with postexpiratory apnea, when compared with the effort associated with the Valsalva maneuver, provides lower elevation of anal pressure at rest by the parameter area under the curve.

Preparative separation of flavonoids from the medicinal plant Davilla elliptica St. Hill. by high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) is a major tool for the fast separation of natural products from plants. It was used for the preparative isolation of the flavonoid monoglucosides present in the aerial parts of the Davilla elliptica St. Hill. (Dilleniaceae). This species is used in Brazilian folk medicine for the treatment of gastric disorders. The optimum solvent system used was composed of a mixture of ethyl acetate-n-propanol-water (140:8:80, v/v/v) and led to a successful separation of quercetin-3-O-alpha-L-rhamnopyranoside and myricetin-3-O-alpha-L-rhamnopyranoside in approximately 3.0 hours with purity higher than 95%. Identification was performed by ¹H NMR, 13C NMR and HPLC-UV-DAD analyses.