Locomotion and Energetics of Divergent Foraging Strategies in Hummingbirds: A Review.

Hummingbirds have two main foraging strategies: territoriality (defending a patch of flowers) and traplining (foraging over routine circuits of isolated patches). Species are often classified as employing one or the other. Not only have these strategies been inconsistently defined within the behavioral literature, but this simple framework also neglects the substantial evidence for flexible foraging behavior displayed by hummingbirds. Despite these limitations, research on hummingbird foraging has explored the distinct avenues of selection that proponents of either strategy presumably face: trapliners maximizing foraging efficiency, and territorialists favoring speed and maneuverability for resource defense. In earlier studies, these functions were primarily examined through wing disc loading (ratio of body weight to the circular area swept out by the wings, WDL) and predicted hovering costs, with trapliners expected to exhibit lower WDL than territorialists and thus lower hovering costs. While these pioneering models continue to play a role in current research, early studies were constrained by modest technology, and the original expectations regarding WDL have not held up when applied across complex hummingbird assemblages. Current technological advances have allowed for innovative research on the biomechanics/energetics of hummingbird flight, such as allometric scaling relationships (e.g., wing area-flight performance) and the link between high burst lifting performance and territoriality. Providing a predictive framework based on these relationships will allow us to reexamine previous hypotheses, and explore the biomechanical trade-offs to different foraging strategies, which may yield divergent routes of selection for quintessential territoriality and traplining. With a biomechanical and morphofunctional lens, here we examine the locomotor and energetic facets that dictate hummingbird foraging, and provide (a) predictions regarding the behavioral, biomechanical, and morphofunctional associations with territoriality and traplining; and (b) proposed methods of testing them. By pursuing these knowledge gaps, future research could use a variety of traits to help clarify the operational definitions of territoriality and traplining, to better apply them in the field.

Automatic segmentation of inorganic nanoparticles in BF TEM micrographs.

Transmission electron microscopy (TEM) represents a unique and powerful modality for capturing spatial features of nanoparticles, such as size and shape. However, poor statistics arise as a key obstacle, due to the challenge in accurately and automatically segmenting nanoparticles in TEM micrographs. Towards remedying this deficit, we introduce an automatic particle picking device that is based on the concept of variance hybridized mean local thresholding. Validation of this new segmentation model is accomplished by applying a program written in Matlab to a database of 150 bright field TEM micrographs containing approximately 2,000 nanoparticles. We compare the results to global thresholding, local thresholding, and manual segmentation. It is found that this novel automatic particle picking device reduces false positives and false negatives significantly, while increasing the number of individual particles picked on regions of particle overlap.

Laparoscopic forceps--a useful tool in revision hip arthroplasty.

During revision hip arthroplasty, distal cement plugs and broken instrument tips in the femoral canal pose quite a challenge. We report the use of laparoscopic forceps to facilitate their removal thereby avoiding complications associated with other methods previously described.

Elder care. A diagnostic model for failure to thrive.

1. Care of the elderly is often complicated by complex, interacting conditions. Major areas of concern for the elderly are malnutrition, depression, and confusion (in the form of dementia or delirium). Malnutrition has been prevalent in both hospitalized and institutionalized elderly. 2. Failure to thrive (FTT) has long been recognized in pediatric patients as a multifaceted syndrome that is primarily a disorder of nutritional status and physical and mental development. The characteristics of FTT in the elderly are undernutrition, loss of physical and cognitive function, and depression. 3. The redefinition and alteration of terms from the infant model of FTT results in three categories of FTT in the elderly--psychosocial, predisposing, and physical, as opposed to the two categories of FTT in infants--the infant and the environment.

Auer rod-like inclusions in circulating lymphoma cells.

Circulating malignant lymphocytes from a 55-year-old woman with small cleaved follicular center cell lymphoma contained azurophilic splinter-shaped cytoplasmic inclusions. By light microscopic and ultrastructural criteria, these structures closely resembled Auer rods found in acute myeloid leukemia; however, the authors could not find cytochemical evidence of lysosomal origin (results were negative for myeloperoxidase, Sudan black B, acid phosphatase, and periodic acid-Schiff). Immunostaining and flow cytometric analysis confirmed a monoclonal IgM-kappa immunophenotype of the circulating malignant lymphoid cells. The inclusions did not show specific immunoglobulin staining by light microscopic or electron microscopic immunostaining techniques. The authors conclude that these membrane-bound inclusions probably represent aberrant lysosomes in the malignant cells.

Cartilaginous metaplasia in calcific aortic valve disease.

In a 49-year-old man, symptoms of aortic valve stenosis developed that required surgical intervention with valve replacement. Pathologic examination of the valve showed severe calcific aortic sclerosis and foci of hyaline cartilage. The authors believe that these foci are secondary to cartilaginous transformation of mesenchymal valvular tissue. This represents abnormal repair of valvular tissue damaged, in this case, by the nodular calcific process of calcific aortic stenosis.

Transient stress lymphocytosis during crisis of sickle cell anemia and emergency trauma and medical conditions. An immunophenotyping study.

Transient absolute lymphocytosis of peripheral blood has been described in "stress"-related emergency trauma and medical conditions. There are no reports of this phenomenon in patients with sickle cell anemia with vaso-occlusive crisis. We studied initial and follow-up immunophenotypic characteristics of 10 adult patients with sickle cell anemia in crisis and 15 adult patients with emergency conditions who presented with absolute lymphocytosis. On admission, both groups demonstrated increases in the numbers of CD20+ B cells and T cells of the CD2, CD4, CD8, and CD56 (NKH-1) phenotypes compared with control values. Findings in both groups of patients mimicked the results of parenteral epinephrine administration: a pan-B and -T lymphocytosis with marked increase in CD56 (fourfold to fivefold) and CD8 cells (threefold to fourfold) as well as moderate increases in CD20 and CD4 cells (twofold), resulting in a decrease in the CD4/CD8 ratio compared with control values. In patients with sickle cell anemia, there was an expected increase in the CD56 and CD4 populations; however, CD8 cells only doubled at the time of crisis. Therefore, the CD4/CD8 ratio was normal compared with control values. CD20+ B cell numbers exceeded those seen in the patients with medical and trauma emergencies. Elevated corticosteroid levels have been measured after injury in previous studies. Parenterally administered cortisol produces a lymphocytopenia after 4 to 6 hours that selectively decreases T cells. At 10 to 38 hours after admission, there was a marked reduction in the number of T cells in both groups of "stressed" patients, probably reflecting at least partial effects of endogenous corticosteroids. In contrast to the patients with medical and trauma emergencies, the mean lymphocyte count in the patients with sickle cell anemia remained elevated in the "high normal" range and consisted of increased numbers of B cells and CD4 cells. This finding persisted in the patients with sickle cell anemia for up to 3 months after presentation. The lymphocyte responses in both groups probably reflect interactions between adrenergic and steroidal factors.

Evaluation and selection of systems for automating clinical operations.

Hospital automation, through the use of a clinical operations system, can provide access to current and accurate information, present information in more usable and understandable formats, and provide better documentation for hospital and third-party use. A properly designed and implemented clinical operations system will result in better patient care, more efficient labor utilization, better liability protection, and the financial survival of the institution.

Automation of the medical chart.

A properly implemented automated charting system should improve patient care by providing patient information in more meaningful formats to assist the nurse and physician in making better, more timely decisions. It should save the nurse's time in collecting and recording data. Most importantly, it should economically benefit the hospital by making the nursing staff more efficient and decrease missed DRG reimbursements. Better charting will also decrease the hospital's exposure to medical liability. Patient charting should be an integral part of a nurse's daily activities, not something added to the end of the shift. The automation of the patient chart should allow the nurse to enter the data into the computer throughout the day without interfering with normal nursing activities. It is evident that a need exists and software is now becoming available to fill that need. The next five years should see automated patient charting as one of the fastest growing areas in medical computing.