Rates of Water Loss and Absorption in Stick Insect Eggs

The thorny devil stick insect (Eurycantha calcarata) of New Guinea has eggs that take four months or more to develop—incredibly long for an insect. Long development times can be a challenge for eggs because of their finite resources, including nutrients, energy to support development, and water. I investigated the physiological mechanisms underlying long development times in stick insect eggs. The first experiment examined rates of water loss and survival of eggs held in different experimental humidities (0, 75, or 100% RH). Eggs dried quickly in the 0% humidity “dry” container; and more slowly in the 75% humidity “intermediate” container. The eggs did not dry out in the 100% “saturated” container and maintained their original mass throughout the experiment. While none of the dry treatment eggs hatched, one of the intermediate treatment eggs did, and nearly all of the saturated eggs hatched. To see if the eggs could reabsorb water, they were dried until they reached 90% of their original mass. Then they were transferred into a 100% humidity or wet cotton treatment. In both cases, the eggs gained some mass, but never returned to their original mass. These experiments show that the eggs require a high humidity to survive, and that they cannot absorb water from their environment. For these eggs, water is a finite resource. Finally, using flow-through respirometry, I measured metabolic rates of eggs during four months of development. Eggs were held in high humidity (100% RH) and their metabolic rates measured every 3 – 4 weeks. Metabolic rates were extraordinarily low early in development but increased near hatching. These data suggest that eggs delay much of their metabolism until late in development. I speculate that this delay in development is a way to keep the eggshell’s conductance to gases low, allowing the eggs to better conserve water

Rates of Water Loss and Metabolism in the Eggs of Stick Insect Eurycantha calcarata

The thorny devil stick insect (Eurycantha calcarata) of New Guinea has eggs that take four months or more to develop—incredibly long for an insect. Long development times can be a challenge for eggs because of their finite resources, including nutrients, energy to support development, and water. I investigated the physiological mechanisms underlying long development times in stick insect eggs. The first experiment examined rates of water loss and survival of eggs held in different experimental humidities (0, 75, or 100% RH). Eggs dried quickly in the 0% humidity “dry” container; and more slowly in the 75% humidity “intermediate” container. The eggs did not dry out in the 100% “saturated” container and maintained their original mass throughout the experiment. While none of the dry treatment eggs hatched, one of the intermediate treatment eggs did, and nearly all of the saturated eggs hatched. To see if the eggs could reabsorb water, they were dried until they reached 90% of their original mass. Then they were transferred into a 100% humidity or wet cotton treatment. In both cases, the eggs gained some mass, but never returned to their original mass. These experiments show that the eggs require a high humidity to survive, and that they cannot absorb water from their environment. For these eggs, water is a finite resource. Finally, using flow-through respirometry, I measured metabolic rates of eggs during four months of development. Eggs were held in high humidity (100% RH) and their metabolic rates measured every 3 – 4 weeks. Metabolic rates were extraordinarily low early in development but increased near hatching. These data suggest that eggs delay much of their metabolism until late in development. I speculate that this delay in development is a way to keep the eggshell’s conductance to gases low, allowing the eggs to better conserve water

Cosmological analogies in the search for new physics in high-energy collisions

In this paper, analogies between multiparticle production in high-energy collisions and the time evolution of the early universe are discussed. A common explanation is put forward under the assumption of an unconventional early state: a rapidly expanding universe before recombination (last scattering surface), followed by the CMB, later evolving up to present days, versus the formation of hidden/dark states in hadronic collisions followed by a conventional QCD parton shower yielding final-state particles. In particular, long-range angular correlations are considered pointing out deep connections between the two physical cases potentially useful for the discovery of new physics.Comment: 9 pages, 5 figure

Photochemical synthesis of oligomeric amphiphiles from alkyl oxoacids in aqueous environments

The aqueous phase photochemistry of a series of amphiphilic α-keto acids with differing linear alkyl chain lengths was investigated, demonstrating the ability of sunlight-initiated reactions to build molecular complexity under environmentally relevant conditions. We show that the photochemical reaction mechanisms for α-keto acids in aqueous solution are robust and generalizable across alkyl chain lengths. The organic radicals generated during photolysis are indiscriminate, leading to a large mixture of photoproducts that are observed using high-resolution electrospray ionization mass spectrometry, but these products are identifiable following literature photochemical mechanisms. The alkyl oxoacids under study here can undergo a Norrish Type II reaction to generate pyruvic acid, increasing the diversity of observed photoproducts. The major products of this photochemistry are covalently bonded dimers and trimers of the starting oxoacids, many of which are multi-tailed lipids. The properties of these oligomers are discussed, including their spontaneous self-assembly into aggregates

Magnetic Phase Transition of the Perovskite-type Ti Oxides

Properties and mechanism of the magnetic phase transition of the perovskite-type Ti oxides, which is driven by the Ti-O-Ti bond angle distortion, are studied theoretically by using the effective spin and pseudo-spin Hamiltonian with strong Coulomb repulsion. It is shown that the A-type antiferromagnetic(AFM(A)) to ferromagnetic(FM) phase transition occurs as the Ti-O-Ti bond angle is decreased. Through this phase transition, the orbital state is hardly changed so that the spin-exchange coupling along the c-axis changes nearly continuously from positive to negative and takes approximately zero at the phase boundary. The resultant strong two-dimensionality in the spin coupling causes a rapid suppression of the critical temperature as is observed experimentally.Comment: 9 pages, 5 figure

Assessment of Trees Outside Forest (TOF) in Selected Makiling Subwatersheds

Trees outside Forest (TOF) are trees, shrubs, bushes including palms that are found in the Food and Agriculture Organization (FAO) other land classification that can be agricultural, urban, or non-agricultural/urban. TOF provide various services and functions that are neither well documented nor given enough attention, hence the need to identify and assess them in agriculture and urban areas outside Mt. Makiling. A SPOT satellite image (2010) covering the Cambantoc, Molawin-Dampalit, and Tigbi subwatersheds of Mt. Makiling was used in the supervised classification of forests, lakes, agriculture, and urban areas. Areas that qualify as other lands were extracted using the classified land types as guides in GIS vector format. Using Google Earth imagery, other lands were digitized and assessed following the FAO decision tree algorithm for TOF and field checking was conducted to validate the tree height in the TOF criteria. Based on the GIS and field assessment, Tigbi and Molawin-Dampalit were found to have TOF on urban land that are mostly fruit trees cultivated for food, landscaping while Cambantoc has TOF on agricultural land and TOF on non-agricultural/urban that are used as farm windbreaks. Findings suggested that TOF contributed to the tree canopy cover in Makiling subwatersheds. Assessment of TOF can be used to account for the ecosystem services it provides which complement those that come from forests and other wooded lands. FAO also recognizes the importance of TOF for local and national food security. TOF, especially fruit trees, are important source of food products for the people

The Effect on Carbon Dioxide Production During Maximal Exercise with Distinct Breathing Mechanisms

Nasal breathing (NB) may lead to lower maximal oxygen uptake (VO2max) compared to oral breathing (OB) or nasal/oral combined breathing (CB) due to a transient increase in the systemic concentration of carbon dioxide (CO2) that can replicate the effects of a hypoxic environment. The exercise intensity at which NB can elicit this response is poorly understood. PURPOSE: To examine the increase in the fractional rate of exhaled CO2 (FECO2) and FEO2 with different breathing conditions during a graded maximal aerobic exercise test (GXT). METHODS: Eight healthy males (21.88 ± 0.46 years) completed 3 GXTs (separated by 48+ hours of recovery) using a different randomly assigned breathing condition (NB, OB, and CB). Participants exercised on a semi-recumbent bicycle at a pedaling speed of 70 rpm, increasing resistance every 2 minutes until volitional fatigue. Following the GXT, participants had a 2-minute recovery. Expired respiratory gases were collected via a metabolic cart. Six time points (40%, 55%, 70%, 85%, 100% VO2max, and recovery) were compared between NB, OB, and CB. Data are presented as mean ± SD. RESULTS: FECO2 was significantly higher during NB than OB at 70% [4.52 ± 0.37 vs. 4.07 ± 0.26%, p = 0.031 and 85% (4.49 ± 0.43% vs. 3.80 ± 0.32%, p = 0.009) of VO2max. Additionally, FECO2 at 100% of VO2max was significantly higher (p = 0.001) during NB (4.33 ± 0.69%) than OB (3.47 ± 0.29%) and CB (3.55 ± 0.19%). The transient change in FECO2 during exercise rapidly changed after the 2-minute recovery, where NB = 3.75 ± 0.71%, OB = 3.38 ± 0.17%, and CB = 3.30 ± 0.27%. FEO2 was significantly lower during NB than OB at 70% (16.34 ± 0.45% vs. 17.04 ± 0.3%, p = 0.011) and 85% (16.50 ± 0.53% vs. 17.32 ± 0.38%, p = 0.009) of VO2max. FEO2 was significantly lower (p = 0.003) during NB (16.66 ± 0.91%) compared to OB (17.67 ± 0.33%) and CB (17.61 ± 0.26%) at 100% VO2max. The transient change in FEO2 during exercise rapidly changed after the 2-minute recovery, where NB = 17.67 ± 1.00%, OB = 18.03 ± 0.23%, and CB = 18.20 ± 0.17%. CONCLUSION: NB elicits an exercised-induced increase in FECO2 that is analogous to a decrease in FEO2 starting at 70% of VO2max. Given the transient increase in FECO2, NB should be considered as a potential breathing method and further explored to replicate a temporary hypoxic environment that could promote a greater exercise adaptation than CB or OB might do

Early detection of influenza outbreaks using the DC Department of Health's syndromic surveillance system

<p>Abstract</p> <p>Background</p> <p>Since 2001, the District of Columbia Department of Health has been using an emergency room syndromic surveillance system to identify possible disease outbreaks. Data are received from a number of local hospital emergency rooms and analyzed daily using a variety of statistical detection algorithms. The aims of this paper are to characterize the performance of these statistical detection algorithms in rigorous yet practical terms in order to identify the optimal parameters for each and to compare the ability of two syndrome definition criteria and data from a children's hospital versus vs. other hospitals to determine the onset of seasonal influenza.</p> <p>Methods</p> <p>We first used a fine-tuning approach to improve the sensitivity of each algorithm to detecting simulated outbreaks and to identifying previously known outbreaks. Subsequently, using the fine-tuned algorithms, we examined (i) the ability of unspecified infection and respiratory syndrome categories to detect the start of the flu season and (ii) how well data from Children's National Medical Center (CNMC) did versus all the other hospitals when using unspecified infection, respiratory, and both categories together.</p> <p>Results</p> <p>Simulation studies using the data showed that over a range of situations, the multivariate CUSUM algorithm performed more effectively than the other algorithms tested. In addition, the parameters that yielded optimal performance varied for each algorithm, especially with the number of cases in the data stream. In terms of detecting the onset of seasonal influenza, only "unspecified infection," especially the counts from CNMC, clearly delineated influenza outbreaks out of the eight available syndromic classifications. In three of five years, CNMC consistently flags earlier (from 2 days up to 2 weeks earlier) than a multivariate analysis of all other DC hospitals.</p> <p>Conclusions</p> <p>When practitioners apply statistical detection algorithms to their own data, fine tuning of parameters is necessary to improve overall sensitivity. With fined tuned algorithms, our results suggest that emergency room based syndromic surveillance focusing on unspecified infection cases in children is an effective way to determine the beginning of the influenza outbreak and could serve as a trigger for more intensive surveillance efforts and initiate infection control measures in the community.</p

Multi-Phonon γ\gamma-Vibrational Bands and the Triaxial Projected Shell Model

We present a fully quantum-mechanical, microscopic, unified treatment of ground-state band and multi-phonon $\gamma$-vibrational bands using shell model diagonalization with the triaxial projected shell model. The results agree very well with data on the g- and $\gamma$-band spectra in $^{156-170}$Er, as well as with recently measured $4^+$ 2-phonon $\gamma$-bandhead energies in $^{166}$Er and $^{168}$Er. Multi-phonon $\gamma$-excitation energies are predicted.Comment: 4 pages, 4 figures, submitted to Phys. Lett.