El efecto del nivel de proteína y lípidos sobre la acción dinámica específica y la excreción postprandial en sub-adultos del camarón blanco Litopenaeus vannamei

The study aimed to evaluate the effect of 4 levels of dietary protein (20, 30, 40 and 50%) and lipids (2, 4, 8 and 16%) on the magnitude and duration of specific dynamic action (SDA) and postprandial nitrogen excretion in the subadult white shrimpLitopenaeus vannameiusing computer-controlled metabolic chambers (continuous-flow respirometer). We determined the oxygen consumption rate at 1 h intervals until the postprandial oxygen consumption rate returned to the pre-feeding level. Shrimp fed all the diets had significantly higher respiration rates after feeding due to the SDA. Oxygen consumption, the SDA coefficient and the SDA magnitude increased notably with increasing dietary protein content. Shrimp fed the 20% protein diet had the lowest levels of pre- and post-feeding respiration and the smallest SDA. A significant change in the SDA coefficient relative to each lipid level was not demonstrable. Additionally, nitrogenous excretion increased with an increase of dietary protein but not with an increase of lipid level. By estimating the SDA of subadults, the response to standard metabolic rate (SMR) was lower than that reported for juveniles and postlarva white shrimp

‘Doing’ hypertension: Experiential knowledge and practice in the self-management of ‘high blood’ in the Philippines

Patients’ embodied experiences do not always correspond to the biomedical concepts of particular diseases. Drawing from year-long fieldwork in the Philippines that involved semi-structured interviews, focus group discussions and digital diaries, we examine how individuals ‘do’ hypertension through their embodied experiences and the knowledge and practice that emerge from them. Drawing inspiration from Annemarie Mol’s work on the notion of ‘multiplicity’ of disease, our analysis was informed by a commitment to privileging patients’ embodied experiences and the multiple ontologies of hypertension. We find that for patients diagnosed with hypertension in the Philippines, symptoms enact illness; patients rely on their own embodied knowledge to define their illness’ nature (e.g., diagnosis), experience (e.g., frequency of symptoms and non-chronicity) and praxis (e.g., self-care practices). We show how this knowledge gained from having embodied experiences of living with the disease interacts in various ways with biomedical knowledge, other diagnostic labels and clinical practices, to shape how hypertension manifests and is managed by patients. Beyond interrogating the relationship between what counts as a ‘disease’ and what is considered a ‘symptom’, our findings underscore the need to pay attention instead to the mutually co-constitutive processes of embodied experiences and disease categories in co-producing patient knowledge

Strengths and Weaknesses of Digital Diaries as a Means to Study Patient Pathways: Experiences With a Study of Hypertension in the Philippines

The rise of digital mobile communications has made possible novel research methods that can provide a better understanding of patients’ experience of non-communicable diseases. This study explores the opportunities and challenges in employing “digital diaries” via mobile phones to track the lived experiences of people with hypertension in the Philippines. Following in-depth interviews, 40 hypertensive adults were invited to submit digital diaries over 12 months. Mobile phones were found to be an efficient way of reaching participants, although it was difficult to collect in-depth narratives about their experiences using the medium beyond nominal responses about symptoms and treatment. Possible explanations include the asymptomatic nature of hypertension, which limited the participants’ experiences of the illness, as well as the platform itself, which our mostly-elderly, low-income participants may not be comfortable with. Despite these challenges, “digital diaries” hold potential for the study of other chronic conditions, provided that researchers engage in extensive co-production with participants to understand their preferences. Researchers also need more training in the use of these methods appropriately as part of a suite of methods for capturing the experience of people living with chronic illness

Participant Use of Digital Diaries in Qualitative Research: A Strong Structuration Analysis

Lived experiences of chronic conditions are marked by fluidity and change, which should be considered if care is to be truly patient-centered. Seeking to capture this fluidity, we used digital diaries via mobile phones to communicate with hypertensive patients in the Philippines over approximately 12 months. This paper draws on Strong Structuration Theory to conceptualize the complex array of factors shaping participants’ usage (and non-usage) of the diaries, thereby offering a comprehensive understanding of how the diaries were perceived and used. We draw on qualitative data from 42 participants (73 baseline/follow-up interviews and 37 digital diaries), purposively selected from a larger pool of quantitative participants, as well as existing literature and our own study documents. The Philippines ‘digital divide\u27 presented barriers to the usage of the diaries, stemming from a lack of access and mobile signal especially in socioeconomically marginalized rural areas. Within this context, the sharing of mobile phones both enabled and constricted diary participation. Guided by Strong Structuration Theory, we observed three cycles of structuration evident in participants’ usage of diaries. The first pertained to the frequency and mode of engagement. A low level of engagement was observed, stemming from negative or ambivalent attitudes toward texting and other factors. Conversely, mobile phone ‘top-ups’ enabled participation. Participant usage of the diaries as tools for monitoring hypertension and to request health advice comprise the second and third structuration cycles. These usages contrast with researchers’ intended usage of the diaries and with the original brief given to participants. The conflict between participants’ and researchers’ understanding of the appropriate uses of the diaries represents the dynamic field of position-practice relations, wherein agents are situated and interact, either perpetuating or challenging existing societal structures. Our findings underline the importance of considering macro- and meso-level factors when considering or conducting research using digital diaries

Aqueous peptide-TiO2 interfaces: iso-energetic binding via either entropically- or enthalpically-driven mechanisms

A major barrier to the systematic improvement of biomimetic peptide-mediated strategies for the controlled growth of inorganic nanomaterials in environmentally benign conditions lies in the lack of clear conceptual connections between the sequence of the peptide and its surface binding affinity, with binding being facilitated by non-covalent interactions. Peptide conformation, both in the adsorbed and non-adsorbed state, is the key relationship that connects peptide-materials binding with peptide sequence. Here, we combine experimental peptide–titania binding characterization with state-of-the-art conformational sampling via molecular simulations to elucidate these structure/binding relationships for two very different titania-binding peptide sequences. The two sequences (Ti-1: QPYLFATDSLIK and Ti-2: GHTHYHAVRTQT) differ in their overall hydropathy, yet via quartz-crystal microbalance measurements and predictions from molecular simulations, we show these sequences both support very similar, strong titania-binding affinities. Our molecular simulations reveal that the two sequences exhibit profoundly different modes of surface binding, with Ti-1 acting as an entropically-driven binder while Ti-2 behaves as an enthalpically-driven binder. The integrated approach presented here provides a rational basis for peptide sequence engineering to achieve the in-situ growth and organization of titania nanostructures in aqueous media and for the design of sequences suitable for a range of technological applications that involve the interface between titania and biomolecules

(De)Constructing ‘Therapeutic Itineraries’ of Hypertension Care: A Qualitative Study in the Philippines

Hypertension, a major risk factor for non-communicable diseases, remains poorly controlled in many countries. In the Philippines, it is still one of the leading causes of preventable deaths despite the accessibility and availability of essential technologies and medicine to detect and treat hypertension. This paper characterizes the ‘therapeutic itineraries’ of people with hypertension from poor communities in rural and urban settings in the Philippines. We employ longitudinal qualitative methodology comprised of repeat interviews and digital diaries using mobile phones from 40 recruited participants in 12 months. Our findings demonstrate that therapeutic itineraries, rather than being organized according to categories that stem from the structure of the health system (i.e., diagnosis, treatment, follow-up, adherence), diverge from clinical pathways. Therapeutic itineraries begin at a stage we label as ‘pre-diagnosis’ (PD). Following this, itineraries diverge according to two possible entry points into the healthcare system: via incidental diagnosis (ID) whereby participants were diagnosed with hypertension without deliberately seeking care for hypertension-related symptoms and symptom-driven diagnosis (SD) whereby their diagnosis was obtained during a clinical encounter specifically prompted by hypertension-related symptoms. Participants whose itineraries follow the SD route typically oscillated between periods of regular and intermittent medical treatment, while participants who were diagnosed incidentally (ID) typically opted for self-care As we follow our participants\u27 therapeutic itineraries, we explore the confluence of factors informing their care journey, namely, their conceptions of hypertension, their social relationships, as well the choices and trade-offs they make. We conclude with policy implications from our findings, chief of which is our proposition that models of care based on mere access and availability of clinical interventions fail to reflect the complexity of people\u27s lay understanding and their lived experiences of hypertension and are thus ultimately unhelpful in improving its control

Orientation dependence of heterogeneous nucleation at the Cu–Pb solid-liquid interface

In this work, we examine the effect of surface structure on the heterogeneous nucleation of Pb crystals from the melt at a Cu substrate using molecular-dynamics (MD) simulation. In a previous work [Palafox-Hernandez et al., Acta Mater. 59, 3137 (2011)] studying the Cu/Pb solid-liquid interface with MD simulation, we observed that the structure of the Cu(111) and Cu(100) interfaces was significantly different at 625 K, just above the Pb melting temperature (618 K for the model). The Cu(100) interface exhibited significant surface alloying in the crystal plane in contact with the melt. In contrast, no surface alloying was seen at the Cu(111) interface; however, a prefreezing layer of crystalline Pb, 2-3 atomic planes thick and slightly compressed relative to bulk Pb crystal, was observed to form at the interface. We observe that at the Cu(111) interface the prefreezing layer is no longer present at 750 K, but surface alloying in the Cu(100) interface persists. In a series of undercooling MD simulations, heterogeneous nucleation of fcc Pb is observed at the Cu(111) interface within the simulation time (5 ns) at 592 K—a 26 K undercooling. Nucleation and growth at Cu(111) proceeded layerwise with a nearly planar critical nucleus. Quantitative analysis yielded heterogeneous nucleation barriers that are more than two orders of magnitude smaller than the predicted homogeneous nucleation barriers from classical nucleation theory. Nucleation was considerably more difficult on the Cu(100) surface-alloyed substrate. An undercooling of approximately 170 K was necessary to observe nucleation at this interface within the simulation time. From qualitative observation, the critical nucleus showed a contact angle with the Cu(100) surface of over 90°, indicating poor wetting of the Cu(100) surface by the nucleating phase, which according to classical heterogeneous nucleation theory provides an explanation of the large undercooling necessary to nucleate on the Cu(100) surface, relative to Cu(111), whose surface is more similar to the nucleating phase due to the presence of the prefreezing layer

Responsive and Equitable Health Systems-Partnership on Non-Communicable Diseases (RESPOND) study: a mixed-methods, longitudinal, observational study on treatment seeking for hypertension in Malaysia and the Philippines.

INTRODUCTION: Hypertension is a leading contributor to the global burden of disease. While safe and effective treatment exists, blood pressure control is poor in many countries, often reflecting barriers at the levels of health systems and services as well as at the broader level of patients' sociocultural contexts. This study examines how these interact to facilitate or hinder hypertension control, taking into account characteristics of service provision components and social contexts. METHODS AND ANALYSIS: The study, set in Malaysia and the Philippines, builds on two systematic reviews of barriers to effective hypertension management. People with hypertension (pre-existing and newly diagnosed) will be identified in poor households in 24-30 communities per country. Quantitative and qualitative methods will be used to examine their experiences of and pathways into seeking and obtaining care. These include two waves of household surveys of 20-25 participants per community 12-18 months apart, microcosting exercises to assess the cost of illness (including costs due to health seeking activities and inability to work (5 per community)), preliminary and follow-up in-depth interviews and digital diaries with hypertensive adults over the course of a year (40 per country, employing an innovative mobile phone technology), focus group discussions with study participants and structured assessments of health facilities (including formal and informal providers). ETHICS AND DISSEMINATION: Ethical approval has been granted by the Observational Research Ethics Committee at the London School of Hygiene and Tropical Medicine and the Research Ethics Boards at the Universiti Putra Malaysia and the University of the Philippines Manila. The project team will disseminate findings and engage with a wide range of stakeholders to promote uptake and impact. Alongside publications in high-impact journals, dissemination activities include a comprehensive stakeholder analysis, engagement with traditional and social media and 'digital stories' coproduced with research participants

Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

No abstract available