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We identified species and approximate size of prey items in 109 digital photographs of North American River Otters (Lontra canadensis) hunting in a 2-km stretch of South Fork Eel River, California, from January 2017 through December 2021. Over the 5-y study, 403 observations of River Otter social-group types and sizes were recorded, including singles, family groups with pups, and groups of up to 8 adults. An average of 3.0 River Otters per week (sx = 0.2, range 1 to 13 individuals) were observed in the study area. Eleven species of prey were taken by River Otters, including primarily, Sacramento Pikeminnow (Ptychocheilus grandis; 54.1% of 109), followed by crayfish spp. (24.8%), Pacific Lamprey (Entosphenus tridentatus; 10.1%), herpetofauna (6.4%), and less-frequently taken fish species (4.6%). Contingency table frequencies indicated Sacramento Pikeminnow and crayfish were taken more in months of low water flows in the river. Herpetofauna prey included 1 American Bullfrog (Lithobates catesbeinus), 2 Foothill Yellow-legged Frogs (Rana boylii), 1 Northwestern Pond Turtle (Actinemys marmorata), and 3 Rough-skinned Newts (Taricha granulosa), apparently with no ill effects to the otters. Sacramento Pikeminnows were captured by social groups of 2 and 3 or more River Otters more often than expected, and by single otters and family groups less often than expected; whereas crayfish were captured by single otters and family groups more often than expected, and by social groups of 2 and 3 or more, less often than expected. Different River Otter social-group types and sizes captured smaller (<30 cm) and larger fish (≥30 cm) at similar frequencies. [ABSTRACT FROM AUTHOR]

The need to accurately document the spatiotemporal distribution of earthquakegenerated strong ground motions is essential for evaluating the seismic vulnerability of sites of critical infrastructure. Understanding the threshold for maximum earthquakeinduced ground motions at such sites provides valuable information to seismologists, earthquake engineers, local agencies, and policymakers when determining ground motion hazards of seismically sensitive infrastructures. In this context, fragile geologic features such as precariously balanced rocks (PBRs) serve as negative evidence for earthquake-induced ground motions and provide important physical constraints on the upper limits of ground motions. The three-dimensional (3D) shape of a PBR is a critical factor in determining its static stability and thus susceptibility to toppling during strong ground shaking events. Furthermore, the geomorphic settings of PBRs provide important controls on PBR exhumation histories that are interpreted from surface exposure dating methods. In this paper, we present PBRslenderness, a MATLAB-based program that evaluates the two-dimensional (2D) static stabilities of PBRs from unconstrained digital photographs. The program's graphical user interface allows users to interactively digitize a PBR and calculates the 2D geometric parameters that define its static stability. A reproducibility study showed that our 2D calculations compare well against their counterparts that were computed in 3D (R2 = 0.77-0.98 for 22 samples). A sensitivity study for single-user and multiuser digitization routines further confirmed the reproducibility of PBRslenderness estimates (coefficients of variation cv = 4.3%-6.5% for 100 runs; R2 = 0.87-0.99 for 20 PBRs). We used PBRslenderness to analyze 261 PBRs in a low-seismicity setting to investigate the local geomorphic controls on PBR stability and preservation. PBRslenderness showed that a PBR's shape strongly controls its static stability and that there is no relationship between a PBR's stability and its geomorphic location in a drainage basin. However, the geomorphic settings of PBRs control their preservation potential by restricting their formation to hillslope gradients <40°and the upper reaches of drainage basins. Such examples of our program's utility have led to its use in archival efforts of PBRs in southern California and Nevada, USA. [ABSTRACT FROM AUTHOR]

Background: T'ai chi chuan, the ancient Chinese martial art, is practiced by millions of people worldwide and is an activity of moderate intensity that involves slow, circular movements. Evidence of substantial health benefits of t'ai chi chuan is emerging, however, the physiologic mechanisms are not well-understood. T'ai chi chuan masters routinely report sensing qi or internal energy flow, particularly in the hands. The purpose of this case study was to determine whether physiologic responses normally associated with thermoregulation are activated during a basic t'ai chi chuan exercise. Methods: Trials consisted of three focus periods and one withdraw period (during which the subject withdrew internal energy in the hands), each followed by a rest period. Measurements included infrared-thermography (IR), thermocoupled temperature measures, and laser Doppler flowmetry. Results: Substantial increases in local palmar and face surface temperatures were observed with IR thermography during focus periods and substantial decreases were observed during the withdraw period. Fingertip surface baseline temperatures were 31.1°C for one trial, increased by 1.8°C during the focus period, and then decreased by 4.9°C during the withdraw period. A twofold increase in blood flow through fingertip regions paralleled changes in fingertip surface temperatures during focus periods. Conclusions: Changes in regional blood flow and surface temperatures closely paralleled onsets of focus, rest, and withdraw periods and appear to be volitional activations of known vasomotor mechanisms underlying non-hairy skin regions such as the hands and face. Changes in blood flow through these vascular structures are generally autonomic thermoregulatory responses, not normally under voluntary control, but may also represent a relaxation response. [ABSTRACT FROM AUTHOR]

Abstract: Savannas are spatially heterogeneous, open ecosystems, thus efforts to quantify canopy structure with methods developed for homogeneous, closed canopies are prone to failure. We examine the applicability of two direct (litterfall, allometry) and five indirect (LAI-2000, TRAC, digital hemispheric photography, digital cover photography, traversing radiometer system) methods to determine leaf area index across a 9ha domain in an oak-savanna ecosystem in California, USA. Interpretation of the leaf area index measurements is supported by two gap-fraction models. We recommend that leaf inclination angle distribution should be characterized first. For this purpose, we propose a simple, reliable and reproducible method using a digital camera. We show that the combination of digital cover photography and LAI-2000 could provide spatially representative leaf area index, gap fraction and element clumping index. Based on these two indirect methods, we quantify spatially representative element clumping index and leaf area index at ecosystem scale as 0.49±0.10 (mean±95% confidence interval) and 0.77±0.27, respectively. In contrast to previous studies in northern ecosystems, measurement and modeling results suggest that element clumping index decreases with view zenith angle, most likely due to apparent changes of tree distribution pattern with the view zenith angle. Our results highlight the importance of ecosystem-scale clumping effects for the adequate quantification of tree leaf area index in savannas. Finally, we suggest a protocol to quantify leaf area index and its associated canopy structure variables in open canopy ecosystems. [Copyright &y& Elsevier]

An interview with artist Glynnis Reed is presented. When asked about the concept of the sublime in her photography, she says that it is about landscape that relates to love with vastness, beauty and complexity. She mentions various qualities that landscape in Los Angeles, California possesses including multiplicity of cultures, the dynamics of culture and experience of people. She also shares how she started using digital tools and added drawing to her work.

The article presents the highlights of a discussion on digital photography as a new art form held during the 1993 conference of the Art Libraries Society of North America in California. Diana Emery Hulick of Arizona explained the human perceptions of reality related to the photographic image. Photojournalist George Wedding cited the role of photography as a historical record. Artist Susan Felter emphasized the influence of computer medium on her art.

The article discusses a ubiquitous computing (UbiSys) workshop held at Ubicomp 2006, the Eighth International Conference of Ubiquitous Computing. The conference was held in Orange County, California, September 17-21, 2006, and hosted by the University of California, Irvine, California. The workshop theme was pervasive image capturing and sharing. Participants used the Zone Tag camera phone application that uploads digital photos to Flickr. The wrap-up discussion revisited open questions including how to provide the most compelling image-sharing experience, and the convergence of image-sharing and social network software. Privacy issues were discussed.