716 research outputs found
Are chimpanzees really so poor at understanding imperative pointing? Some new data and an alternative view of canine and ape social cognition
There is considerable interest in comparative research on different species’ abilities to respond to human communicative cues such as gaze and pointing. It has been reported that some canines perform significantly better than monkeys and apes on tasks requiring the comprehension of either declarative or imperative pointing and these differences have been attributed to domestication in dogs. Here we tested a sample of chimpanzees on a task requiring comprehension of an imperative request and show that, though there are considerable individual differences, the performance by the apes rival those reported in pet dogs. We suggest that small differences in methodology can have a pronounced influence on performance on these types of tasks. We further suggest that basic differences in subject sampling, subject recruitment and rearing experiences have resulted in a skewed representation of canine abilities compared to those of monkeys and apes
The plight of the sense-making ape
This is a selective review of the published literature on object-choice tasks, where participants use directional cues to find hidden objects. This literature comprises the efforts of researchers to make sense of the sense-making capacities of our nearest living relatives. This chapter is written to highlight some nonsensical conclusions that frequently emerge from this research. The data suggest that when apes are given approximately the same sense-making opportunities as we provide our children, then they will easily make sense of our social signals. The ubiquity of nonsensical contemporary scientific claims to the effect that humans are essentially--or inherently--more capable than other great apes in the understanding of simple directional cues is, itself, a testament to the power of preconceived ideas on human perception
Intricacies in the surgical management of appendiceal mucinous cystadenoma: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Mucinous cystadenoma is a type of mucocele of the appendix that is rarely encountered in clinical practice. Dogmatic consensus on the optimal surgical modus operandi of appendicular mucocele is lacking in the literature and this remains a subject of controversy. There is little agreement with regard to the best procedure (right hemicolectomy versus appendectomy) or the best surgical approach (laparoscopic versus laparotomy).</p> <p>Case presentation</p> <p>We report the case of a 70-year-old Asian woman from Karachi who presented with pain in the right iliac fossa for 15 days. On physical examination, a mobile and firm mass was palpable in the right iliac fossa. A colonoscopy was performed which showed external compression of the cecum. A biopsy of the mucosa was normal. Computed tomography scan showed a mucocele of the appendix with minimal periappendiceal fat stranding. She underwent an initial diagnostic laparoscopy to evaluate any mucin spillage in the peritoneal cavity. Once no spillage was identified, an open appendectomy was then performed. Intra-operatively, a frozen section of the appendiceal sample was sent to ascertain the need for an extension of surgery to a right hemicolectomy. Absence of any malignancy on the frozen section obviated the need for a surgical extension. The final histopathological examination showed a mucinous cystadenoma of the appendix. The patient was symptom-free at one year after surgery.</p> <p>Conclusion</p> <p>It is important to distinguish between mucinous cystadenomas and mucinous cystadenocarcinomas. However, this distinction remains elusive in the pre-operative setting. A simple appendectomy using an intra-operative frozen section appears to be a reasonable surgical approach for selected cases with an intact mucocele of the appendix. However, long-term follow-up is warranted in such patients to evaluate the risks of using this approach.</p
Influencing the properties of dysprosium single-molecule magnets with phosphine, phosphide and phosphinidene ligands
Single-molecule magnets are a type of coordination compound that can retain magnetic information at low temperatures. Single-molecule magnets based on lanthanides have accounted for many important advances, including systems with very large energy barriers to reversal of the magnetization, and a di-terbium complex that displays magnetic hysteresis up to 14 K and shows strong coercivity. Ligand design is crucial for the development of new single-molecule magnets: organometallic chemistry presents possibilities for using unconventional ligands, particularly those with soft donor groups. Here we report dysprosium single-molecule magnets with neutral and anionic phosphorus donor ligands, and show that their properties change dramatically when varying the ligand from phosphine to phosphide to phosphinidene. A phosphide-ligated, trimetallic dysprosium single-molecule magnet relaxes via the second-excited Kramers’ doublet, and, when doped into a diamagnetic matrix at the single-ion level, produces a large energy barrier of 256 cm1 and magnetic hysteresis up to 4.4 K
Complement C5a induces renal injury in diabetic kidney disease by disrupting mitochondrial metabolic agility
The sequelae of diabetes include microvascular complications such as diabetic kidney disease (DKD), which involves glucose-mediated renal injury associated with a disruption in mitochondrial metabolic agility, inflammation, and fibrosis. We explored the role of the innate immune complement component C5a, a potent mediator of inflammation, in the pathogenesis of DKD in clinical and experimental diabetes. Marked systemic elevation in C5a activity was demonstrated in patients with diabetes; conventional renoprotective agents did not therapeutically target this elevation. C5a and its receptor (C5aR1) were upregulated early in the disease process and prior to manifest kidney injury in several diverse rodent models of diabetes. Genetic deletion of C5aR1 in mice conferred protection against diabetes-induced renal injury. Transcriptomic profiling of kidney revealed diabetes-induced downregulation of pathways involved in mitochondrial fatty acid metabolism. Interrogation of the lipidomics signature revealed abnormal cardiolipin remodeling in diabetic kidneys, a cardinal sign of disrupted mitochondrial architecture and bioenergetics. In vivo delivery of an orally active inhibitor of C5aR1 (PMX53) reversed the phenotypic changes and normalized the renal mitochondrial fatty acid profile, cardiolipin remodeling, and citric acid cycle intermediates. In vitro exposure of human renal proximal tubular epithelial cells to C5a led to altered mitochondrial respiratory function and reactive oxygen species generation. These experiments provide evidence for a pivotal role of the C5a/C5aR1 axis in propagating renal injury in the development of DKD by disrupting mitochondrial agility, thereby establishing a new immunometabolic signaling pathway in DKD
Importance of Glycosylation on Function of a Potassium Channel in Neuroblastoma Cells
The Kv3.1 glycoprotein, a voltage-gated potassium channel, is expressed throughout the central nervous system. The role of N-glycans attached to the Kv3.1 glycoprotein on conducting and non-conducting functions of the Kv3.1 channel are quite limiting. Glycosylated (wild type), partially glycosylated (N220Q and N229Q), and unglycosylated (N220Q/N229Q) Kv3.1 proteins were expressed and characterized in a cultured neuronal-derived cell model, B35 neuroblastoma cells. Western blots, whole cell current recordings, and wound healing assays were employed to provide evidence that the conducting and non-conducting properties of the Kv3.1 channel were modified by N-glycans of the Kv3.1 glycoprotein. Electrophoretic migration of the various Kv3.1 proteins treated with PNGase F and neuraminidase verified that the glycosylation sites were occupied and that the N-glycans could be sialylated, respectively. The unglycosylated channel favored a different whole cell current pattern than the glycoform. Further the outward ionic currents of the unglycosylated channel had slower activation and deactivation rates than those of the glycosylated Kv3.1 channel. These kinetic parameters of the partially glycosylated Kv3.1 channels were also slowed. B35 cells expressing glycosylated Kv3.1 protein migrated faster than those expressing partially glycosylated and much faster than those expressing the unglycosylated Kv3.1 protein. These results have demonstrated that N-glycans of the Kv3.1 glycoprotein enhance outward ionic current kinetics, and neuronal migration. It is speculated that physiological changes which lead to a reduction in N-glycan attachment to proteins will alter the functions of the Kv3.1 channel
Differential Effects of Attention-, Compassion-, and Socio-Cognitively Based Mental Practices on Self-Reports of Mindfulness and Compassion
Research on the effects of mindfulness- and compassion-based interventions is flourishing along with self-report scales to assess facets of these broad concepts. However, debates remain as to which mental practices are most appropriate to develop the attentional, cognitive, and socio-affective facets of mindfulness and compassion. One crucial question is whether present-moment, attention-focused mindfulness practices are sufficient to induce a cascade of changes across the different proposed facets of mindfulness, including nonjudgmental acceptance, as well as compassion or whether explicit socio-affective training is required. Here, we address these questions in the context of a 9-month longitudinal study (the ReSource Project) by examining the differential effects of three different 3-month mental training modules on subscales of mindfulness and compassion questionnaires. The “Presence” module, which aimed at cultivating present-moment-focused attention and body awareness, led to increases in the observing, nonreacting, and presence subscales, but not to increases in acceptance or nonjudging. These latter facets benefitted from specific cultivation through the socio-cognitive “Perspective” module and socio-affective, compassion-based “Affect” module, respectively. These modules also led to further increases in scores on the subscales affected by the Presence module. Moreover, scores on the compassion scales were uniquely influenced by the Affect module. Thus, whereas a present-moment attention-focused training, as implemented in many mindfulness-based programs, was indeed able to increase attentional facets of mindfulness, only socio-cognitive and compassion-based practices led to broad changes in ethical-motivational qualities like a nonjudgmental attitude, compassion, and self-compassion
- …