Remote delivery of a weight management intervention for adults with intellectual disabilities: Results from a randomized non-inferiority trial.

BACKGROUND: Remote delivery of multi-component weight management interventions results in clinically meaningful weight loss in adults without intellectual disabilities (ID), but the effectiveness of remotely delivered weight management interventions in adults with ID has not previously been evaluated. OBJECTIVE: To determine if a weight management intervention delivered remotely could achieve weight loss (kg) at 6 months that is non-inferior to in-person visits in adults with ID and overweight or obesity (BMI ≥25 kg/m2). METHODS: Participants were randomized to a 24-mo. trial (6 mos weight loss,12 mos weight maintenance, 6 mos. no-contact follow up) to compare weight loss achieved with the same multicomponent intervention delivered to individual participants in their home either remotely (RD) or during face-to-face home visits (FTF). RESULTS: One hundred twenty adults with ID (∼32 years of age, 53 % females) were randomized to the RD (n = 60) or the FTF arm (n = 60). Six-month weight loss in the RD arm (-4.9 ± 7.8 kg) was superior to 6-month weight loss achieved in the FTF arm (-2.1 ± 6.7 kg, p = 0.047). However, this may be partially attributed to the COVID-19 pandemic, since weight loss in the FTF arm was greater in participants who completed the intervention entirely pre-COVID (n = 33,-3.2 %) compared to post-COVID (n = 22, -0.61 %). Weight loss across did not differ significantly between intervention arms at 18 (p = 0.33) or 24 months (p = 0.34). CONCLUSION: Our results suggest that remote delivery is a viable option for achieving clinically relevant weight loss and maintenance in adults with ID. NCT REGISTRATION: NCT03291509.

Decoding collective communications using information theory tools.

Organisms have evolved sensory mechanisms to extract pertinent information from their environment, enabling them to assess their situation and act accordingly. For social organisms travelling in groups, like the fish in a school or the birds in a flock, sharing information can further improve their situational awareness and reaction times. Data on the benefits and costs of social coordination, however, have largely allowed our understanding of why collective behaviours have evolved to outpace our mechanistic knowledge of how they arise. Recent studies have begun to correct this imbalance through fine-scale analyses of group movement data. One approach that has received renewed attention is the use of information theoretic (IT) tools like mutual information, transfer entropy and causation entropy, which can help identify causal interactions in the type of complex, dynamical patterns often on display when organisms act collectively. Yet, there is a communications gap between studies focused on the ecological constraints and solutions of collective action with those demonstrating the promise of IT tools in this arena. We attempt to bridge this divide through a series of ecologically motivated examples designed to illustrate the benefits and challenges of using IT tools to extract deeper insights into the interaction patterns governing group-level dynamics. We summarize some of the approaches taken thus far to circumvent existing challenges in this area and we conclude with an optimistic, yet cautionary perspective.

Ingesta de líquidos e hidratación en personas mayores no institucionalizadas en un municipio de Valencia (España) / Ingestion of liquids and hydration in non-institutionalized older peoplein a municipality of Valencia (Spain)

FUNDAMENTOS: El consumo de agua y líquidos a lo largo del día es un factor de vital importancia para la hidratación del ser humano. Las personas mayores presentan una especial vulnerabilidad hídrica. El objetivo del estudio es determinar la ingesta de líquidos y el estado de hidratación a nivel comunitario de una población mayor no institucionalizada. MÉTODOS: Estudio transversal mediante encuesta y observación de la orina de una muestra de conveniencia de 82 personas (23 hombres y 59 mujeres) entre 65y 89 años, del municipio de Silla (Valencia).Se estimó la ingesta media diaria de líquidos, el tipo de bebidas consumidas con mayor frecuencia mediante cuestionario validado de frecuencia de ingesta líquida(PREDIMED). El grado de hidratación según el color de la orina (colorimetría) de una muestra de la primera orina del día. Se ha relacionado la deshidratación por colorimetría con las variables sexo, edad (65-74 años, y 75-89años), convivencia y volumen total ingerido. RESULTADOS: La ingesta media de líquidos fue de 1.846 ml/persona/día (DE=531),similar entre las mujeres, 1.918 ml/día (DE=552), y los hombres 1.658 ml/día(DE=428). La prevalencia de deshidratación estimada fue del 46,34%, mayor(p<0,05) en hombres (91,30%) que en mujeres (44,74%). Por grupos de edad, la prevalencia fue de 55% en los mayores de 75 años y de 38,10% entre los 65 y 74años. Un 72,73% de las personas que presentaban deshidratación ingería menos de 1.500 ml de líquidos al día. CONCLUSIONES: La alta prevalencia de signos urinarios de deshidratación observada en la muestra, justifica la realización de actuaciones comunitarias para el fomento de una adecuada hidratación centrada en personas mayores de 75 años y con el objetivo de aumentar la ingesta de líquidos diaria por encima de los 1500 ml

BACKGROUND: The consumption of water and liquids throughout the day is a factor of vital importance for the hydration of the human being. Older people have a special water vulnerability. The objective of the study is to determine the intake of fluids and the state of hydration at the community level of a larger non-institutionalized population. METHODS: Cross-sectional study by means of a survey and observation of the urine of a convenience sample of 82 people (23 men and 59 women) between 65 and 89 years old, from the municipality of Silla (Valencia) The average daily intake of liquids was estimated, the type of drinks consumed most frequently by means of a validated questionnaire on the frequency of liquid intake (PREDIMED). The degree of hydration according to the color of the urine (colorimetry) of a sample of the first urine of the day. Dehydration has been related to colorimetry with the variables sex, age (65-74 years, and 75-89 years), coexistence and total volume ingested. RESULTS: The average fluid intake was 1,846 ml / person / day (SD = 531), similar among women, 1,918 ml / day (SD = 552), and men 1,658 ml / day (SD = 428). The estimated prevalence of dehydration was 46.34%, higher (p <0.05) in men (91.30%) than in women (44.74%). By age groups, the prevalence was 55% in those over 75 years of age and 38.10% in those between 65 and 74 years of age. A 72.73% of people who had dehydration ingested less than 1,500 ml of fluids per day. CONCLUSIONS: The high prevalence of urinary signs of dehydration observed in the sample, justifies the performance of community actions for the promotion of adequate hydration focused on people over 75 years and with the aim of increasing the daily fluid intake above 1500 ml

Spiritual Uncertainty Among Hospice Providers: "There Were Tensions".

How providers of end-of-life care perceive spirituality both within themselves and for others can directly impact their ability to provide spiritual care to patients and families. Uncertainty about spirituality can contribute to the awkwardness of spiritual care. Spiritual uncertainty includes the questions, worries, and doubts people have about the meaning, beliefs, connections, self-transcendence, and value that comprise spirituality. This article reports qualitative findings from a mixed-methods study that sought to understand spiritual uncertainty among hospice providers. Data were collected from 28 hospice team members (nurses, physicians, social workers, and expressive therapist) using focus groups, reflective journals, and one-on-one interviews. An overarching theme emerged that described the tensions perceived by providers caring for hospice patients. Those tensions were further categorized as being interpersonal, intrapersonal, and transpersonal in nature. The identification of tension as a source of strain for providers delivering spiritual care is necessary to the development of future interventions that can assist providers and patients navigating end-of-life spirituality.

Weight management for adolescents with intellectual and developmental disabilities: Rationale and design for an 18month randomized trial.

Adolescents with intellectual and developmental disabilities (IDD) are an underserved group in need of weight management. However, information regarding effective weight management for this group is limited, and is based primarily on results from small, non-powered, non-randomized trials that were not conducted in accordance with current weight management guidelines. Additionally, the comparative effectiveness of emerging dietary approaches, such as portion-controlled meals (PCMs) or program delivery strategies such as video chat using tablet computers have not been evaluated. Therefore, we will conduct an 18month trial to compare weight loss (6months) and maintenance (7-18months) in 123 overweight/obese adolescents with mild to moderate IDD, and a parent, randomized to a weight management intervention delivered remotely using FaceTime™ on an iPad using either a conventional meal plan diet (RD/CD) or a Stop Light diet enhanced with PCMs (RD/eSLD), or conventional diet delivered during face-to-face home visits (FTF/CD). This design will provide an adequately powered comparison of both diet (CD vs. eSLD) and delivery strategy (FTF vs. RD). Exploratory analyses will examine the influence of behavioral session attendance, compliance with recommendations for diet (energy intake), physical activity (min/day), self-monitoring of diet and physical activity, medications, and parental variables including diet quality, physical activity, baseline weight, weight change, and beliefs and attitudes regarding diet and physical activity on both weight loss and maintenance. We will also complete a cost and contingent valuation analysis to compare costs between RD and FTF delivery.

An Examination of Interactions between Hospice Health Care Providers and Adolescents with a Parent in Hospice.

Interviews conducted with adolescents living with a dying parent were examined to identify the type of interactions the adolescents had with members of a hospice healthcare team. Four types of interactions were identified: No Interactions, In-passing Interactions, Engaged Interactions, and Formal Interactions. Results indicated that most of the adolescents had no contact with the hospice healthcare team or interacted with providers only briefly. Some adolescents reported more engagement with one or more hospice healthcare team members, and a few received formal counseling services from the hospice healthcare team or outside provider. Overall, limited contact occurred because of logistics or because the teens perceived that hospice services were exclusively targeted to dying patients, not their families. Based on these findings, strategies to increase engagement between adolescents and hospice healthcare team are discussed.

The melioidosis agent Burkholderia pseudomallei and related opportunistic pathogens detected in faecal matter of wildlife and livestock in northern Australia.

The Darwin region in northern Australia has experienced rapid population growth in recent years, and with it, an increased incidence of melioidosis. Previous studies in Darwin have associated the environmental presence of Burkholderia pseudomallei, the causative agent of melioidosis, with anthropogenic land usage and proximity to animals. In our study, we estimated the occurrence of B. pseudomallei and Burkholderia spp. relatives in faecal matter of wildlife, livestock and domestic animals in the Darwin region. A total of 357 faecal samples were collected and bacteria isolated through culture and direct DNA extraction after enrichment in selective media. Identification of B. pseudomallei, B. ubonensis, and other Burkholderia spp. was carried out using TTS1, Bu550, and recA BUR3-BUR4 quantitative PCR assays, respectively. B. pseudomallei was detected in seven faecal samples from wallabies and a chicken. B. cepacia complex spp. and Pandoraea spp. were cultured from wallaby faecal samples, and B. cenocepacia and B. cepacia were also isolated from livestock animals. Various bacteria isolated in this study represent opportunistic human pathogens, raising the possibility that faecal shedding contributes to the expanding geographical distribution of not just B. pseudomallei but other Burkholderiaceae that can cause human disease.

A virtual reality intervention (Second Life) to improve weight maintenance: Rationale and design for an 18-month randomized trial.

Despite the plethora of weight loss programs available in the US, the prevalence of overweight and obesity (BMI≥25kg/m(2)) among US adults continues to rise at least, in part, due to the high probability of weight regain following weight loss. Thus, the development and evaluation of novel interventions designed to improve weight maintenance are clearly needed. Virtual reality environments offer a promising platform for delivering weight maintenance interventions as they provide rapid feedback, learner experimentation, real-time personalized task selection and exploration. Utilizing virtual reality during weight maintenance allows individuals to engage in repeated experiential learning, practice skills, and participate in real-life scenarios without real-life repercussions, which may diminish weight regain. We will conduct an 18-month effectiveness trial (6 months weight loss, 12 months weight maintenance) in 202 overweight/obese adults (BMI 25-44.9kg/m(2)). Participants who achieve ≥5% weight loss following a 6month weight loss intervention delivered by phone conference call will be randomized to weight maintenance interventions delivered by conference call or conducted in a virtual environment (Second Life®). The primary aim of the study is to compare weight change during maintenance between the phone conference call and virtual groups. Secondarily, potential mediators of weight change including energy and macronutrient intake, physical activity, consumption of fruits and vegetables, self-efficacy for both physical activity and diet, and attendance and completion of experiential learning assignments will also be assessed.

Two worlds: Adolescents' strategies for managing life with a parent in hospice.

OBJECTIVE: This study aimed to generate an explanatory model of the coping strategies that adolescents employ to manage the stressors they experience in the final months of their ill parent's life and shortly after their death. METHOD: The sample included 26 families of adolescents with a parent receiving care in a large hospice program in northeastern Ohio. A semistructured interview was conducted with 14 ill parents, 17 well parents/guardians, and 30 of their adolescent children before the parent's death and, additionally, with 6 of these families after the death. The interviews were audiotaped, transcribed verbatim, and analyzed using a grounded-theory approach. RESULTS: The participants described two worlds that constituted the lives of the adolescents: the well world of normal adolescence and the ill world of having a parent near the end of life. The adolescents experienced a common challenge of living in two worlds and responded to the challenge with a process we labeled "managing two worlds." Five stages through which adolescents manage their worlds were identified: keeping the ill world and the well world separate; having the ill world intrude into the well world; moving between the ill world and the well world; being immersed in the ill world; and returning to the well world having been changed by the ill world. SIGNIFICANCE OF RESULTS: The explanatory model of "managing two worlds" outlines a complex and nuanced process that changes over time. The model can be used by health professionals who seek to help adolescents navigate this critical time when their parents are dying or have recently died. These results can also be used to inform the development of interventions that assist families with strategies tailored to an adolescent's specific needs. Future research should investigate associations among the process of "managing two worlds" and outcomes related to adolescent bereavement.

Melioidosis in New Caledonia: a dominant strain in a transmission hotspot.

Melioidosis is an infectious disease caused by Burkholderia pseudomallei, a bacterium endemic in Southeast Asia and northern Australia. In New Caledonia, sporadic cases were first described in 2005; since then, more cases have been identified. To improve our understanding of melioidosis epidemiology in New Caledonia, we compared the local cases and B. pseudomallei isolates with those from endemic areas. Nineteen melioidosis cases have been diagnosed in New Caledonia since 1999, mostly severe and with frequent bacteraemia, leading to three (16%) fatalities. All but one occurred in the North Province. Besides sporadic cases caused by non-clonal strains, we also identified a hotspot of transmission related to a clonal group of B. pseudomallei that is phylogenetically related to Australian strains.

Parental relationships beyond the grave: Adolescents' descriptions of continued bonds.

OBJECTIVE: Many people experience an ongoing relationship with a deceased loved one. This is called a "continued bond." However, little is known about the adolescent experience with continued bonds once a parent has died. This study describes three ways that adolescents continue their relationship with a parent after that parent's death. METHOD: Individual semistructured interviews were conducted with nine adolescent children of deceased hospice patients from a large hospice in northeastern Ohio as part of a larger grounded-theory study. The interviews were audiotaped, transcribed verbatim, and analyzed using a conventional content analysis approach. RESULTS: Adolescents continued their bonds with deceased parents in one of three ways: experiencing encounters with the deceased parent, listening to the inner guide of the parent, and keeping mementos to remind them of the parent. SIGNIFICANCE OF RESULTS: The ways that the adolescents continued their bond with a deceased parent assisted them in creating meaning out of their loss and adjusting to life without that parent. Our results can be used by health professionals and parents to help adolescents after a parent has died.

Uncertainties experienced by family members when one parent is dying.

PURPOSE: This research examined uncertainty as a salient theme for families in which a parent was dying while receiving hospice care. METHODS: Interviews were conducted with 61 participants from 26 families in the parent study to explore the strategies used by adolescents with a parent in a hospice. Second interviews were conducted with 15 original participants after the death of their parent. Conventional content analysis was used to analyse data. RESULTS: Uncertainty was a prevalent and salient theme in the participants' stories revealing patterns about the causes, barriers, effects and strategies used to manage uncertainty. CONCLUSION: Uncertainties associated with the end of life can be problematic for some people, requiring attention by health professionals.

Short range order in elemental liquids of column IV.

The short range order (SRO) in liquid elements of column IV is analysed within the quasi-crystalline model across a wide range of temperatures. It is found that l-Si, Ge, and Sn are well described with a beta-tin like SRO. In contrast, Pb retains a bcc-like SRO similar to other simple elemental liquids. However, a distinction is found between the SRO in Si and Ge and that in Sn, where the latter has a more rigid structure. This difference persists across the entire temperature range examined but is overcome in Si at pressures above 8 GPa, where the liquid structure evolves towards that of Sn.

Exploring family relationships through associations of comfort, relatedness states, and life closure in hospice patients: A pilot study.

OBJECTIVE: Research at the end of life tends to focus on the dying patient's symptoms, often overlooking issues associated with family interactions. However, many families struggle just to maintain or initiate these valuable connections. The purpose of our pilot study was to explore family relationships at the end of life and investigate associations among perceived comfort, relatedness states, and life closure. METHOD: This descriptive study used a cross-sectional design, and a convenience sample (n = 30; 18 women; mean age = 71 years) was recruited from patients admitted to a large not-for-profit hospice in northeastern Ohio. In-person interviews using the Hospice Comfort Questionnaire, Relatedness States Visual Analog Scales, and the Life-Closure Scale provided data for analyses. RESULTS: Family interactions that were not associated with the physical tasks of caregiving were related to life closure (r = 0.36, p = 0.001), and life closure and comfort were highly correlated (r = 0.69, p < 0.001). Participants residing in an inpatient setting had higher levels of involvement (t[18] = -2.07, p = 0.05) and comfort in relationships (t[28] = -2.06, p = 0.05) than those in the home setting. SIGNIFICANCE OF RESULTS: This is the first known study investigating the associations among comfort, relatedness, and life closure at the end of life. The majority of participants had high levels of involvement and comfort in their relationships, and they preferred interactions that required minimal effort. Studies that focus on both patients' and family members' perceptions of relationships are needed as well as outcome studies that test simple interventions.

Regulation of the mitogen-activated protein kinase kinase (MEK)-1 by NAD(+)-dependent deacetylases.

Sirtuins are class III deacetylases that regulate many essential processes, including cellular stress, genome stability and metabolism. Although these NAD(+)-dependent deacetylases control adaptive cellular responses, identification of sirtuin-regulated signaling targets remain under-studied. Here, we demonstrate that acetylation of the mitogen-activated protein kinase kinase-1 (MEK1) stimulates its kinase activity, and that acetylated MEK1 is under the regulatory control of the sirtuin family members SIRT1 and SIRT2. Treatment of cells with sirtuin inhibitors, or siRNA knockdown of SIRT1 or SIRT2 proteins, increases MEK1 acetylation and subsequent phosphorylation of the extracellular signal-regulated kinase. Generation of an acetyl-specific MEK1 antibody demonstrates that endogenous acetylated MEK1 is extensively enriched in the nucleus following epidermal growth factor  stimulation. An acetyl-mimic of MEK1 increases inappropriate growth properties, suggesting that acetylation of MEK1 has oncogenic potential.

Calentamiento neuromuscular estructurado como prevención de lesiones en futbolistas profesionales jóvenes / Structured neuromuscular warm-up for injury prevention in young elite football players

Objetivo. Recopilar evidencia sobre los resultados de los programas de calentamiento neuromuscular estructurados sin equipo adicional como método de prevención de lesiones de no contacto en futbolistas jóvenes profesionales. Material y métodos. Se realizó durante marzo y abril de 2013 una búsqueda de literatura (PubMed, Biblioteca Cochrane Plus, The American Journal Sports of Medicine, The British Journal of Sports Medicine y el motor de búsqueda Trip Database). Resultados. Se obtuvieron, tras aplicar los criterios de inclusión y exclusión, un total de 6 estudios (3 ensayos clínicos, un estudio de cohortes y 2 revisiones sistemáticas). El programa «FIFA 11+» mostró una reducción de lesiones en un 33-57%, desgranándose en un 52% en rodilla, 22% en tobillo, 40% en síndrome de estrés medial tibial, 50% en muslo posterior y 21% en el anterior, y 12% en la zona inguinal. El programa «FIFA 11» mostró una reducción del 58% en esguinces de tobillo y del 27% en lesiones de LCA. Otros programas específicos de prevención de lesiones de LCA las redujeron en un 74% y «Knäkontroll, SISU Idrottsböcker©» en un 64%. El programa «HarmoKnee» redujo lesiones de rodilla en un 78%. Discusión. Se observaron varias debilidades metodológicas, pero parece que existe la tendencia a que un calentamiento que contenga como base estiramientos, fortalecimiento y ejercicios de equilibrio, realizado durante más de tres meses y de manera regular podría prevenir lesiones. Conclusiones. El programa «FIFA 11+» podría ser una buena medida preventiva de lesiones aplicando su programa de calentamiento estructurado. A pesar de ello, nuevos estudios mejor diseñados se requieren para poder valorar bien esta evidencia (AU)

Objective. To gather evidence about the outcomes of structured neuromuscular warm-up programs without additional equipment, as prevention of non-contact injuries in young professional soccer players. Material and methods. A literature search was conducted during March and April 2013 (PubMed, Cochrane Library, The American Journal of Sports Medicine, The British Journal of Sports Medicine and the search engine Trip Database). Results. After applying the inclusion and exclusion criteria, a total of 6 studies were obtained (3 clinical trials, one cohort study and 2 systematic reviews). «FIFA 11+» program showed a reduction of injuries of between 33% and 57%. These included 52% in knee, 22% in ankle, 40% in medial tibial stress syndrome, 50% in posterior thigh, and 21% in the anterior, and 12% in the groin area. «FIFA 11» program showed a 58% reduction in ankle sprains and 27% in anterior cruciate ligament (ACL) injuries. Other specific programs to prevent ACL injuries reduced them by 74% and «Knäkontroll, SISU Idrottsböcker©» by 64%. «HarmoKnee» program reduced knee injuries by 78%. Discussion. Several methodological weaknesses were observed, but it seems that there is a trend toward a warm-up that contains basic stretching, strengthening and balance exercises, which performed for more than three months and regularly, could prevent injuries. Conclusions. «FIFA 11 +» program might be a good preventive measure of injuries by implementing its program of structured warm- up. In any event new, better designed, studies are needed to assess this evidence (AU)

[Structured neuromuscular warm-up for injury prevention in young elite football players]. / Calentamiento neuromuscular estructurado como prevención de lesiones en futbolistas profesionales jóvenes.

OBJECTIVE: To gather evidence about the outcomes of structured neuromuscular warm-up programs without additional equipment, as prevention of non-contact injuries in young professional soccer players. MATERIAL AND METHODS: A literature search was conducted during March and April 2013 (PubMed, Cochrane Library, The American Journal of Sports Medicine, The British Journal of Sports Medicine and the search engine Trip Database). RESULTS: After applying the inclusion and exclusion criteria, a total of 6 studies were obtained (3 clinical trials, one cohort study and 2 systematic reviews). "FIFA 11+" program showed a reduction of injuries of between 33% and 57%. These included 52% in knee, 22% in ankle, 40% in medial tibial stress syndrome, 50% in posterior thigh, and 21% in the anterior, and 12% in the groin area. "FIFA 11" program showed a 58% reduction in ankle sprains and 27% in anterior cruciate ligament (ACL) injuries. Other specific programs to prevent ACL injuries reduced them by 74% and "Knäkontroll, SISU Idrottsböcker©" by 64%. "HarmoKnee" program reduced knee injuries by 78%. DISCUSSION: Several methodological weaknesses were observed, but it seems that there is a trend toward a warm-up that contains basic stretching, strengthening and balance exercises, which performed for more than three months and regularly, could prevent injuries. CONCLUSIONS: "FIFA 11 +" program might be a good preventive measure of injuries by implementing its program of structured warm- up. In any event new, better designed, studies are needed to assess this evidence.

Telling adolescents a parent is dying.

BACKGROUND: When a parent is terminally ill, one of the major challenges facing families is informing children of the parent's condition and prognosis. This study describes four ways in which parents disclose information about a parent's life-threatening illness to their adolescent children. METHODS: We audio-recorded and transcribed 61 individual interviews with hospice patients who were recruited from a large hospice in northeastern Ohio, their spouses/partners, and their adolescent children. The interviews were coded and analyzed using a constant comparison approach. RESULTS AND CONCLUSIONS: Families inform adolescents about the progression of a parent's terminal illness in characteristic ways that remain fairly consistent throughout the illness, and are aimed at easing the adolescents' burden and distress. The families engaged in the process of disclosure in one of four ways: measured telling, skirted telling, matter-of-fact telling, and inconsistent telling. These results will inform the development of interventions that assist families with disclosure and are tailored to each family's communication style.

Liquid structure and temperature invariance of sound velocity in supercooled Bi melt.

Structural rearrangement of liquid Bi in the vicinity of the melting point has been proposed due to the unique temperature invariant sound velocity observed above the melting temperature, the low symmetry of Bi in the solid phase and the necessity of overheating to achieve supercooling. The existence of this structural rearrangement is examined by measurements on supercooled Bi. The sound velocity of liquid Bi was measured into the supercooled region to high accuracy and it was found to be invariant over a temperature range of ∼60°, from 35° above the melting point to ∼25° into the supercooled region. The structural origin of this phenomenon was explored by neutron diffraction structural measurements in the supercooled temperature range. These measurements indicate a continuous modification of the short range order in the melt. The structure of the liquid is analyzed within a quasi-crystalline model and is found to evolve continuously, similar to other known liquid pnictide systems. The results are discussed in the context of two competing hypotheses proposed to explain properties of liquid Bi near the melting: (i) liquid bismuth undergoes a structural rearrangement slightly above melting and (ii) liquid Bi exhibits a broad maximum in the sound velocity located incidentally at the melting temperature.

Short range order in liquid pnictides.

Liquid pnictides have anomalous physical properties and complex radial distribution functions. The quasi-crystalline model of liquid structure is applied to interpret the three-dimensional structure of liquid pnictides. It is shown that all the column V elements can be characterized by a short range order lattice symmetry similar to that of the underlying solid, the A7 structure, which originates from a Peierls distorted simple cubic lattice. The evolution of the liquid structure down the column as well as its temperature and pressure dependence is interpreted by means of the effect of thermodynamic parameters on the Peierls distortion. Surprisingly, it is found that the Peierls effect increases with temperature and the nearest neighbour distances exhibit negative thermal expansion.