Perfect State Transfer in Laplacian Quantum Walk

For a graph $G$ and a related symmetric matrix $M$, the continuous-time quantum walk on $G$ relative to $M$ is defined as the unitary matrix $U(t) = \exp(-itM)$, where $t$ varies over the reals. Perfect state transfer occurs between vertices $u$ and $v$ at time $\tau$ if the $(u,v)$-entry of $U(\tau)$ has unit magnitude. This paper studies quantum walks relative to graph Laplacians. Some main observations include the following closure properties for perfect state transfer: (1) If a $n$-vertex graph has perfect state transfer at time $\tau$ relative to the Laplacian, then so does its complement if $n\tau$ is an integer multiple of $2\pi$. As a corollary, the double cone over any $m$-vertex graph has perfect state transfer relative to the Laplacian if and only if $m \equiv 2 \pmod{4}$. This was previously known for a double cone over a clique (S. Bose, A. Casaccino, S. Mancini, S. Severini, Int. J. Quant. Inf., 7:11, 2009). (2) If a graph $G$ has perfect state transfer at time $\tau$ relative to the normalized Laplacian, then so does the weak product $G \times H$ if for any normalized Laplacian eigenvalues $\lambda$ of $G$ and $\mu$ of $H$, we have $\mu(\lambda-1)\tau$ is an integer multiple of $2\pi$. As a corollary, a weak product of $P_{3}$ with an even clique or an odd cube has perfect state transfer relative to the normalized Laplacian. It was known earlier that a weak product of a circulant with odd integer eigenvalues and an even cube or a Cartesian power of $P_{3}$ has perfect state transfer relative to the adjacency matrix. As for negative results, no path with four vertices or more has antipodal perfect state transfer relative to the normalized Laplacian. This almost matches the state of affairs under the adjacency matrix (C. Godsil, Discrete Math., 312:1, 2011).Comment: 26 pages, 5 figures, 1 tabl

Trends in admissions, morbidity and outcomes at Red Cross War Memorial Children’s Hospital, Cape Town, 2004 - 2013

Background. Routinely collected patient information has the potential to yield valuable information about health systems and population health, but there have been few comprehensive analyses of paediatric admissions at South African (SA) hospitals.Objectives. To investigate trends in hospitalisation and outcomes at Red Cross War Memorial Children’s Hospital (RCWMCH), a major referral hospital for children in the Western Cape and SA.Methods. Using routinely collected observational health data from the hospital informatics system, we investigated admissions between 2004 and 2013. Clinical classification software was used to group International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) codes to rank causes during 2008 - 2013, when ICD-10 codes were widely available. Analyses examined trends in medical and surgical admissions over time.Results. There were 215 536 admissions over 10 years of 129 733 patients. Admissions increased by 9.3%, with increases in the general medical wards (5%), medical specialty wards (74%), the burns unit (73%), and the intensive care unit (16%). In contrast, admissions decreased in the trauma unit (21%) and short-stay medical wards (1%). In-hospital mortality decreased by 54% (p-trend <0.001) over 10 years. Diarrhoea and lower-respiratory tract illness were the most common causes for medical admissions, although admissions and deaths due to these conditions decreased between 2008 and 2013, which coincided with the national introduction of related vaccines. Similarly, tuberculosis admissions and deaths decreased over this period. These trends could be owing to a concurrent decrease in HIV comorbidity (p-trend <0.001). Trauma was the most common reason for surgical admission.Conclusion. Paediatric in-hospital mortality decreased consistently over a decade, despite an overall increase in admissions. Pneumonia and diarrhoea admissions decreased markedly over a 6-year period, but remain the most important causes of hospitalisation

The effectiveness of injury prevention programs to modify risk factors for non-contact anterior cruciate ligament and hamstring injuries in uninjured team sports athletes: A systematic review

Background Hamstring strain and anterior cruciate ligament injuries are, respectively, the most prevalent and serious non-contact occurring injuries in team sports. Specific biomechanical and neuromuscular variables have been used to estimate the risk of incurring a non-contact injury in athletes. Objective The aim of this study was to systematically review the evidences for the effectiveness of injury prevention protocols to modify biomechanical and neuromuscular anterior cruciate and/or hamstring injuries associated risk factors in uninjured team sport athletes. Data Sources PubMed, Science Direct, Web of Science, Cochrane Libraries, U.S. National Institutes of Health clinicaltrials.gov, Sport Discuss and Google Scholar databases were searched for relevant journal articles published until March 2015. A manual review of relevant articles, authors, and journals, including bibliographies was performed from identified articles. Main Results Nineteen studies were included in this review. Four assessment categories: i) landing, ii) side cutting, iii) stop-jump, and iv) muscle strength outcomes, were used to analyze the effectiveness of the preventive protocols. Eight studies using multifaceted interventions supported by video and/or technical feedback showed improvement in landing and/or stop-jump biomechanics, while no effects were observed on side-cutting maneuver. Additionally, multifaceted programs including hamstring eccentric exercises increased hamstring strength, hamstring to quadriceps functional ratio and/or promoted a shift of optimal knee flexion peak torque toward a more open angle position. Conclusions Multifaceted programs, supported by proper video and/or technical feedback, including eccentric hamstring exercises would positively modify the biomechanical and or neuromuscular anterior cruciate and/or hamstring injury risk factors

Social inclusion and professional female migrants in multicultural Australia

The goal of the thesis is to scrutinise the experiences of professional female migrants in Australia. The study was undertaken in the context of the emergence of a policy focus on ‘social inclusion’ and ‘social exclusion’ in Australia and elsewhere and in the context of renewed debates in Australia about multiculturalism. Social inclusion refers to a policy focus on enabling the full participation of citizens in the life of the nation, including economic, social, cultural and political participation (Gillard & Wong, 2007). In turn, social exclusion refers to a policy focus on identifying and addressing groups whose participation is constrained, often measured along the dimensions of consumption, production, political engagement, social support and cultural life (see for example, Burchardt, Le Grand, & Piachaud, 2002; Richardson & Le Grand, 2002). This research is interested in testing the relevance of these frameworks for understanding and addressing the experiences of professional female migrants in multicultural Australia. The thesis involved a study of twenty professional female migrants living in Sydney who participated in in-depth interviews. All respondents belonged to a highly skilled occupational group and a prerequisite was that they held a primary professional qualification before migration to Australia. Participants, who were from both English speaking and non-English speaking backgrounds provided detailed narratives of their lives and experiences since migration to Australia, and these narratives provided a window into the specificities of professional female migrants’ perceptions of moving to Australia, settling in Australia and ‘belonging’ in Australia. These insights add to the body of knowledge on migration and social inclusion and exclusion. The research found that the relevance of the dominant social inclusion framework for analysing their migration and settlement experiences is only partial: this is because of the prioritisation of economic participation as a route to social inclusion. The social inclusion framework, consequently, fails to recognise the cultural dimension of social inclusion by assuming that social inclusion in multicultural Australia can be achieved and maintained through the active economic participation of Australian citizens. In addition, the study found that the dominant social inclusion policy framework does not recognise an important aspect of professional female migrants’ identity: transnational relationships and transnational belonging. In terms of the specificities of professional female migrants’ experiences, the thesis proposes a structure for talking about differences in experiences of inclusion that uses measures such as participation in paid work, either in mainstream or in ethno-specific workplaces; participation in social life, either in or in and beyond their own ethnic community; self-perception of being, or not being, included - a dimension that was often based on whether or not they experienced racism. Based on these factors, women’s experiences could be categorised as varying between deep, borderline, marginal and shallow inclusion. The thesis also finds that although social inclusion does not equal assimilation or a transition from being a migrant, social inclusion is possible in the context of ethnic and cultural differences

Effects of jump and balance training on knee kinematics and electromyography of female basketball athletes during a single limb drop landing: pre-post intervention study

<p>Abstract</p> <p>Background</p> <p>Some research studies have investigated the effects of anterior cruciate ligament (ACL) injury prevention programs on knee kinematics during landing tasks; however the results were different among the studies. Even though tibial rotation is usually observed at the time of ACL injury, the effects of training programs for knee kinematics in the horizontal plane have not yet been analyzed. The purpose of this study was to determine the effects of a jump and balance training program on knee kinematics including tibial rotation as well as on electromyography of the quadriceps and hamstrings in female athletes.</p> <p>Methods</p> <p>Eight female basketball athletes participated in the experiment. All subjects performed a single limb landing at three different times: the initial test, five weeks later, and one week after completing training. The jump and balance training program lasted for five weeks. Knee kinematics and simultaneous electromyography of the rectus femoris and Hamstrings before training were compared with those measured after completing the training program.</p> <p>Results</p> <p>After training, regarding the position of the knee at foot contact, the knee flexion angle for the Post-training trial (mean (SE): 24.4 (2.1) deg) was significantly larger than that for the Pre-training trial (19.3 (2.5) deg) (p < 0.01). The absolute change during landing in knee flexion for the Post-training trial (40.2 (1.9) deg) was significantly larger than that for the Pre-training trial (34.3 (2.5) deg) (p < 0.001). Tibial rotation and the knee varus/valgus angle were not significantly different after training. A significant increase was also found in the activity of the hamstrings 50 ms before foot contact (p < 0.05).</p> <p>Conclusions</p> <p>The jump and balance training program successfully increased knee flexion and hamstring activity of female athletes during landing, and has the possibility of producing partial effects to avoid the characteristic knee position observed in ACL injury, thereby preventing injury. However, the expected changes in frontal and transverse kinematics of the knee were not observed.</p

Why fencers should bounce: a new method of movement to engage the stretch-shortening cycle

While teaching a heel first contact style of footwork in fencing (also referred to as toe contribution avoidance) is in keeping with long standing traditions, it is not conducive to today’s modern style of fast paced and explosive fencing. Equally, fencers towards the elite-end seem to be gradually adopting a more spring-based style, as their body progressively and organically transitions to “ball of the foot” based footwork, in order for them to fence competitively in the manner they have intuitively associated with success. Therefore, if from a young age fencers are taught to make full use of the stretch shortening cycle (SSC) via “bouncing” or simply by initiating movement via the ball of the foot, this will expedite the learning process. It will demonstrate to them how the SSC can be used to move at greater speed, cover greater distances when advancing, retreating and lunging, and conserve the much-needed energy required to compete over day long competitions. This paper details the mechanistic underpinnings of the SSC and its application to the modern day fencer

What Qualities Are Most Important to Making a Point of Care Test Desirable for Clinicians and Others Offering Sexually Transmitted Infection Testing?

To investigate the possible effects of different levels of attributes of a point-of-care test (POCT) on sexually transmitted infection (STI) professionals' decisions regarding an ideal POCT for STI(s).An online survey was designed based on a large-scale in-depth focus discussion study among STI experts and professionals. The last section of the survey "build your own POCT" was designed by employing the discrete choice experiment approach. Practicing clinicians from two venues, STI-related international conference attendees and U.S. STD clinic clinicians were invited to participate in the survey. Conditional logistical regression modeling was used for data analysis.Overall, 256 subjects took the online survey with 218 (85%) completing it. Most of the participants were STD clinic clinicians who already used some POCTs in their practice. "The time frame required" was identified as a major barrier that currently made it difficult to use STI POCTs. Chlamydia trachomatis was the organism chosen as the top priority for a new POCT, followed by a test that would diagnose early seroconversion for HIV, and a syphilis POCT. Without regard to organism type selected, sensitivity of 90-99% was always the most important attribute to be considered, followed by a cost of $20. However, when the test platform was prioritized for early HIV seroconversion or syphilis, sensitivity was still ranked as most important, but specificity was rated second most important.STI professionals preferred C. trachomatis as the top priority for a new POCT with sensitivity over 90%, low cost, and a very short completion time

Short and long term retention in antiretroviral care in health facilities in rural Malawi and Zimbabwe.

Despite the successful scale-up of ART services over the past years, long term retention in ART care remains a major challenge, especially in high HIV prevalence and resource-limited settings. This study analysed the short (<12 months) and long (>12 months) term retention on ART in two ART programmes in Malawi (Thyolo district) and Zimbabwe (Buhera district)

Non-Sexual Transmission of Trichomonas vaginalis in Adolescent Girls Attending School in Ndola, Zambia

OBJECTIVES: To identify risk factors for trichomoniasis among young women in Ndola, Zambia. METHOD: The study was a cross-sectional study among adolescent girls aged 13-16 years in Ndola, Zambia. Study participants were recruited from schools in selected administrative areas that represented the different socio-economic strata in town. Consenting participants were interviewed about their socio-demographic characteristics; sexual behaviour; and hygiene practices. Self-administered vaginal swabs were tested for Trichomonas vaginalis. HSV-2 antibodies were determined on serum to validate the self-reported sexual activity. RESULTS: A total of 460 girls participated in the study. The overall prevalence of trichomoniasis was 27.1%, 33.9% among girls who reported that they had ever had sex and 24.7% among virgins. In multivariate analysis the only statistically significant risk factor for trichomoniasis was inconsistent use of soap. For the virgins, none of the risk factors was significantly associated with trichomoniasis, but the association with use of soap (not always versus always) and type of toilet used (pit latrine/bush versus flush toilet) was of borderline significance. CONCLUSION: We found a high prevalence of trichomoniasis in girls in Ndola who reported that they had never had sex. We postulate that the high prevalence of trichomoniasis in virgins in Ndola is due to non-sexual transmission of trichomoniasis via shared bathing water and inconsistent use of soap