Termites manipulate moisture content of wood to maximize foraging resources

Animals use cues to find their food, in microhabitats within their physiological tolerances. Termites build and modify their microhabitat, to transform hostile environments into benign ones, which raises questions about the relative importance of cues. Termites are desiccation intolerant and foraging termites are attracted to water, so most research has considered moisture to be a cue. However, termites can also transport water to food, and so moisture may play other roles than previously considered. To examine the role of moisture, we compared Coptotermes acinaciformis termite foraging decisions in laboratory experiments when they were offered dry and moist wood, with and without load. Without load, termites preferred moist wood and ate it without any building, whereas they moistened dry wood after wrapping it in a layer of clay. For the 'With load' units, termites substituted some of the wood for load-bearing clay walls, and kept the wood drier than on the unloaded units. As drier wood has higher compressive strength and higher rigidity, it allows more of the wood to be consumed. These results suggest that moisture plays a more important role in termite ecology than previously thought. Termites manipulate the moisture content according to the situational context and use it for multiple purposes: increased moisture levels soften the fibre, which facilitates foraging, yet keeping the wood dry provides higher structural stability against buckling which is especially important when foraging on wood under load.

The grazing gait, and implications of toppling table geometry for primate footfall sequences

Many medium and large herbivores locomote forwards very slowly and intermittently when grazing. While the footfall order during grazing is the same as for walking, the relative fore-hind timing-phasing-is quite different. Extended periods of static stability are clearly required during grazing; however, stability requirements are insufficient to account for the timing. Aspects of relatively rapid rolling and pitching-toppling due to the resistance of the back to bending and twisting-can be included in a simplifying geometric model to explain the observation that, in grazing livestock, a step forward with a forefoot is consistently and immediately followed by a step forward from the hind; but not vice versa. The same principles and geometry, but applied to the footfall pattern of walking primates, show that toppling would occur at a different point in the gait cycle. This provides a potential account for the distinctive diagonal-sequence footfall pattern of primates, as it prevents the instant of toppling from being at forefoot placement. Careful and controlled hand positioning would thus be facilitated, presumably beneficial to walking on top of branches, despite a slight energetic cost compared with the usual lateral sequence pattern of horses.

Right versus left side bridge static endurance ability among healthy collegiate students at Taibah University

BACKGROUND

Spinal muscles endurance is fundamental for providing adequate trunk stability.

OBJECTIVE

The purpose of this study was to compare the side bridge static endurance ability of the right versus left side.

METHODS

Forty right hand dominant students, aged between 18 and 25 years, were recruited from Taibah University. Every participant had to lie down on his side and bear trunk weight on the arm with shoulder abducted to 90∘ and elbow flexed to 90∘. Every participant had to lift off his trunk of the supporting surface, keeping the trunk straight in neutral position, breathing normally and holding on that position as long as tolerated.

RESULTS

A paired sample t test was calculated. The mean score, in seconds, for right side bridge was 41.6 (SD = 30.08), and for left side bridge was 38.00 (SD = 26.93). No significant difference was found between right and left side bridge endurance ability [t (39) = 1.67, p> 0.05]. Pearson correlation showed high positive correlation [r (38) = 0.89, p< 0.001].

CONCLUSIONS

Among healthy participants, clinicians should expect very close endurance profile for the musculature of the two sides of trunk. Clinicians should equally train both sides of trunk muscles stabilizers in order to enhance tolerance.

Congestus Mode Invigoration by Convective Aggregation in Simulations of Radiative-Convective Equilibrium

This study examines how the congestus mode of tropical convection is expressed in numerical simulations of radiative-convective equilibrium (RCE). We draw insights from the ensemble of cloud-resolving models participating in the RCE Model Intercomparison Project (RCEMIP) and from a new ensemble of two-dimensional RCE simulations. About half of the RCEMIP models produce a congestus circulation that is distinct from the deep and shallow modes. In both ensembles, the congestus circulation strengthens with large-scale convective aggregation, and in the 2D ensemble this comes at the expense of the shallow circulation centered at the top of the boundary layer. Congestus invigoration occurs because aggregation dries out the upper troposphere, which allows moist congestus outflow to undergo strong radiative cooling. The cooling generates divergence that promotes continued congestus overturning (a positive feedback). This mechanism is fundamentally similar to the driving of shallow circulations by radiative cooling at the top of the surface boundary layer. Aggregation and congestus invigoration are also associated with enhanced static stability throughout the troposphere, but a modeling experiment shows that enhanced stability is not necessary for congestus invigoration; rather, invigoration itself contributes to the stability increase via its impact on the vertical profile of radiative cooling. Changes in entrainment cooling are also found to play an important role in stability enhancement, as has been suggested previously. When present, congestus circulations have a large impact on the mean RCE atmospheric state; for this reason, their inconsistent representation in models and their impact on the real tropical atmosphere warrant further scrutiny.

Overweight and Obesity: Its Impact on Foot Type, Flexibility, Foot Strength, Plantar Pressure and Stability in Children from 5 to 10 Years of Age: Descriptive Observational Study

BACKGROUND

Overweight (OW) and childhood obesity (OB) may cause foot problems and affect one's ability to perform physical activities. The study aimed to analyze the differences in descriptive characteristics, foot type, laxity, foot strength, and baropodometric variables by body mass status and age groups in children and, secondly, to analyze the associations of the BMI with different physical variables by age groups in children.

METHODS

A descriptive observational study involving 196 children aged 5-10 years was conducted. The variables used were: type of foot, flexibility, foot strength and baropodometric analysis of plantar pressures, and stability by pressure platform.

RESULTS

Most of the foot strength variables showed significant differences between the normal weight (NW), OW and OB groups in children aged between 5 and 8. The OW and OB groups showed the highest level of foot strength. In addition, the linear regression analyses showed, in children aged 5 to 8 years, a positive association between BMI and foot strength (the higher the BMI, the greater the strength) and negative association between BMI and stability (lower BMI, greater instability).

CONCLUSIONS

Children from 5 to 8 years of age with OW and OB show greater levels of foot strength, and OW and OB children from 7 to 8 years are more stable in terms of static stabilometrics. Furthermore, between 5 and 8 years, having OW and OB implies having more strength and static stability.

Analysis of Spinal Dysfunction in Breast Cancer Survivors with Lymphedema

Background:

To study and analyse the spinal dysfunction in breast cancer survivors with lymphedema.

Methods:

This study was carried out by analysing total 116 breast cancer survivor women, who were having lymphedema. Out of 116 subjects, 39 undergone radical mastectomy (RM), 39 undergone modified radical mastectomy (MRM) and 38 undergone breast conserving surgery (BCS). Thesesubjects were assessed for spinal function bytaking range of motionusing goniometer, lymphedema measurement usinginch tape, spinal stability test and functional rating index.

Results:

The spinal range of motion wassignificantly reduced in patients suffering from lymphedema in breast cancer survivors. The strength and endurance were significantly reduced in abdominals, extensors and lateral muscles of spine. There wasmarked effect seen on quality of life of patients assessed by using functional rating index due to spinal dysfunction in lymphedema patients.

Conclusion:

This study showed that there is statistically significant spinal dysfunction caused due to lymphedema in breast cancer survivors.