Divergent Conditions Research Articles

Texas Rural Land Market Integration: A Causal Analysis using Machine Learning Applications

Texas rural land markets have several special features that makes it unique from other rural land markets in the United States. In 2021, Texas agricultural land, including buildings, is valued at $299.88 billion, which is almost 10% of the nation's total agricultural real estate value and 83% of the state's land is categorized as rural. In addition, due to its size and geologic features, Texas’ diverse landscape creates complex and widely divergent conditions affecting ownership and marketing of the land. Despite this complexity, lack of granular level and reliable transactional data on land sales has prevented thorough investigation into Texas land markets to uncover various interdependencies. Using quarterly transactional land value data from 1966-2017, this study uses cutting-edge machine learning algorithms and probabilistic graphical models to uncover causal interaction patterns of different land markets in Texas. The results reveal that Texas rural land markets are interdependent. Current and potential landholders and lenders can use the results from this work to aid strategic decision making. Financial institutions and investment groups could be made aware of the trend of one land market relative to other markets and adjust their holdings accordingly. Landowners may better understand changes in net wealth, which affect their ability to borrow capital and operate efficiently. Moreover, lenders may also benefit from the information to manage collateral and thus maintain the stability of their operation.

Weighted twisted inhomogeneous diophantine approximation

Abstract We prove a multidimensional weighted analogue of the well-known theorem of Kurzweil (1955) in the metric theory of inhomogeneous Diophantine approximation. Let ∑ i = 1 m α i = m and | ⋅ | α = max 1 ⩽ i ⩽ m | ⋅ | 1 / α i . Given an n-tuple of monotonically decreasing functions Ψ = ( ψ 1 , … , ψ n ) with ψ i : R + → R + such that each ψ i ( r ) → 0 as r → ∞ and fixed A ∈ R n × m define W A ( Ψ ) := { b ∈ [ 0 , 1 ] n : | A i ⋅ q − b i − p i | < ψ i ( | q | α ) ( 1 ⩽ i ⩽ n ) , for infinitely many ( p , q ) ∈ Z n × ( Z m ∖ { 0 } ) } . We prove that the set W A ( Ψ ) has zero-full Lebesgue measure under convergent–divergent sum conditions with some mild assumptions on A and the approximating functions Ψ. We also prove the Hausdorff dimension results for this set. Along with some geometric arguments, the main ingredients are the weighted ubiquity and weighted mass transference principle introduced recently by Kleinbock & Wang (2023 Adv. Math. 428 109154), and Wang & Wu (2021 Math. Ann. 381 243–317) respectively.

Patterns and Drivers of Pollen Temperature Tolerance.

Pollen, a pivotal stage in the plant reproductive cycle, is highly sensitive to temperature fluctuations, impacting seed quality and quantity. While the importance of understanding pollen temperature limits (Tmin, Topt, Tmax - collectively PTLs) is recognized, a comprehensive synthesis of underlying drivers is lacking. Here, we examined PTLs, correlating them with vegetative tissue thermotolerance and assessing variability at the intra- and interspecific levels across 191 species with contrasting phylogeny, cultivation history, growth form and ecology. At the species level, the PTLs range from 9.0 to 42.4°C, with considerable differences among individual species. Vegetative tissue showed greater tolerance to both low and high temperatures than pollen. A significant, though weak, correlation was observed between PTLs and leaf temperature tolerance. Pollen heat tolerance was independent of that in leaves and stems. The greatest intraspecific variability was observed in pollen cold tolerance (Tmin), followed by Topt and Tmax. Phylogenetic analysis revealed family-level conservation in all three pollen temperature tolerance measures. Climate emerged as a significant PTL driver of pollen cold tolerance, with species from colder and stable climates exhibiting enhanced cold tolerance. Cultivated and wild species did not differ in their pollen temperature tolerances. Herbaceous plants showed higher tolerance to high temperatures compared to shrubs and trees, potentially reflecting divergent thermal conditions during anthesis. This study provides the first formal analysis of complex relationships between pollen temperature limits, plant characteristics and environmental factors, providing crucial insights into climate change impacts on plant reproduction.

Can recent evolutionary history promote resilience to environmental change?

Principles of social evolution have long been used retrospectively to interpret social interactions, but have less commonly been applied predictively to inform conservation and animal husbandry strategies. We investigate whether differences in developmental environment, facilitated by divergent social conditions, can predict resilience to environmental change. Upon exposure to harsh novel environments, populations that previously experienced more benign social environments are predicted either to suffer fitness losses (the "mutation load hypothesis" and "selection filter hypothesis") or maintain fitness (the "beneficial mutation hypothesis"). We tested these contrasting predictions using populations of burying beetles Nicrophorus vespilloides we had evolved experimentally for 45 generations under contrasting social environments by manipulating the supply of post-hatching parental care. We exposed sexually immature adults from each population to varying heat stress and measured the effect on survival and reproduction. The greater the level of parental care previously experienced by a population, the better its survival under heat stress during sexual maturation. Although this is consistent with the "beneficial mutation hypothesis," it is also possible that populations that had evolved without post-hatching care were simply more prone to dying during maturation, regardless of their thermal environment. Overall, we suggest that stochastic genetic variation, probably due to founder effects, had a stronger influence on resilience. We discuss the implications for translocation and captive breeding programs.

Evaluating genotype by environment interaction for growth traits in Limousine cattle

Environmental conditions affect the growth and health of animals, making it crucial to quantify heat stress and the genetic basis of heat tolerance in animal breeding. The main objective of this study was to evaluate heat stress on growth and investigate the genetic background of tolerance to harsh environmental conditions in the Italian Limousine beef cattle. Three growth traits were analysed: average daily gain (ADG), weaning weight (WW), and yearling weight (YW). Data were collected from animals raised between 1991 and 2022 and combined with 14 environmental covariates. Records for ADG, WW, and YW encompassed 108 205, 100 058, and 24 939 individuals, respectively, with 4 617, 4 670, and 2 048 genotyped individuals. Climatic variables were compared for inclusion in a linear mixed model using the Deviance Information Criterion. Multiple-trait models and genomic information incorporated environmental conditions with the largest impact on the studied traits Genotype by environment interaction (G × E) was detected in all the studied traits, showing substantial heterogeneity of the variance components across the different environments (Env). Heritability for WW remains constant among Env; instead, for ADG and YW decreased under uncomfortable environmental conditions. YW showed the lowest genetic correlation (0.28) between divergent conditions (Env 2 and Env 5,) for ADG and WW correlations dropped below 0.50 among Env. The values of genetic correlations indicate that growth traits are moderately to strongly affected by G × E. Eigenvalue decomposition of the additive genetic (co)variance matrix for ADG, WW, and YW indicated that three components accounted for over 0.80 of the proportion of the variance explained, suggesting different animal performances across Env. Spearman rank correlations showed potential re-ranking of genotyped sires, because ADG, WW, and YW showed correlations between Env below 0.80. The accuracy of single-step genomic EBV was higher compared to EBV for al traits. Overall, the result confirms the existence of G × E for growth traits in the Italian Limousine population. Including G × E in the model allows for more environment-aware predictions, helping breeders understand how different genetic bases respond to varying conditions. Genomic predictions incorporating G × E could accelerate genetic gains and improve response to selection for heat tolerance.

Physician’s prosodic behavior and the regulation of patient anxiety: A quantitative study within the communication accommodation theory framework

ObjectivesPatients commonly experience anxiety when visiting a medical provider. While regulating its level, the physician may adjust their own prosodic behavior to express different levels of affective empathy and shape the emotional outcome. The primary aim was to examine the impact of convergence and divergence with the patient’s prosodic emotional cues on the patient-perceived physician’s affective empathy and the emotion regulation process. MethodsAnalog patients (n = 132) made assessments after the exposure to an audio vignette of a physician – patient conversation in the prosodic convergence or divergence condition. ResultsConvergence with the prosodic cues of anxiety was associated with the physician experiencing the same as or a similar emotional state to the patient. The former type of emotional reaction was related to lower odds of anxiety alleviation. Prosodic convergence had a negative effect on anxiety alleviation through the mediation of experiencing the same emotional state as the patient. ConclusionsDivergence from the prosodic cues of anxiety and, therefore, a low patient-perceived level of this emotion may facilitate the anxiety regulation process. Practice implicationsA careful use of convergence and divergence with prosodic emotional cues and adequate control of prosody in general are strongly recommended for practitioners.

Analytical Linearization of Aerodynamic Loads in Unsteady Vortex-Lattice Method for Nonlinear Aeroelastic Applications

This paper presents the analytical linearization of aerodynamic loads (computed with the unsteady vortex-lattice method), which is formulated as tangent matrices with respect to the kinematic states of the aerodynamic grid. The loads and their linearization are then mapped to a nonlinear structural model by means of radial-basis functions, allowing for a two-way strong interaction scheme. The structural model comprises geometrically exact beams formulated in a director-based total Lagrangian description, circumventing the need for rotational degrees of freedom. The structural model is spatially discretized into finite elements and temporally discretized with the help of an implicit scheme that identically preserves momenta and energy. The resulting nonlinear discrete equations are solved by applying Newton’s method, requiring calculating the Jacobians of the whole aeroelastic system. The correctness of the linearized loads is then shown by direct comparison with their numerical counterparts. In addition, we employ our strongly coupled aeroelastic model to investigate the nonlinear static and dynamic behavior of a suspension bridge. With this approach, we successfully investigate the numerical features of the aeroelastic system under divergence and flutter conditions.

Intramuscular administration of fractalkine modulates mitochondrial properties and promotes fast glycolytic phenotype.

A newly categorized myokine called fractalkine (CX3CL1) has been associated with divergent conditions such as obesity, tissue inflammation, and exercise. CX3CL1 works through specific membrane-bound receptors (CX3CR1) found in various tissues including skeletal muscles. Studies indicate CX3CL1 induces muscles to uptake energy substrates thereby improving glucose utilization and countering diabetes. Here, we tested if the administration of purified CX3CL1 directly into mice skeletal muscles affects its histoarchitecture, mitochondrial activity, and expression of metabolic proteins. We analyzed four muscles: two upper-limb (quadriceps, hamstrings) and two lower-limb (tibialis anterior, gastrocnemius), contralateral leg muscles were taken as controls. The effects of CX3CL1 treatment on histoarchitecture, mitochondrial activity, and expression of metabolic proteins in muscles were characterized. We used histochemical staining succinate dehydrogenase (SDH)/cytochrome c oxidase (COX), myosin ATPase, alkaline phosphatase (ALP) to evaluate the mitochondrial activity, fiber types, and vascularization in the muscles, respectively. Western blotting was used to evaluate the expression of proteins associated with mitochondrial metabolism (OXPHOS), glycolysis, and vascularization. Overall, this study indicates CX3CL1 primarily modulates mitochondrial metabolism and shifts substrate preference toward glucose in the skeletal muscle. Evidence also supports that CX3CL1 stimulates the relative composition of fast fiber types, influencing selection of energy substrates in the skeletal muscle.

Numerical investigation of the divergence-free constraint for the miscible fluids interaction in a lock-exchange arrangement

The present work scrutinizes the implementation of the divergence-free constraint in miscible fluids flow algorithms. In general, the flow solvers handling the interaction of the miscible fluid enforce the zero divergence condition, considering the fluids to be incompressible. In these algorithms, however, a convection-diffusion equation for the mass fraction, in conjunction with the Navier-Stokes equation, is solved for incorporating the mixing effects. This equation leads to a non-zero velocity field in the numerical modeling and the derived velocity divergence is a function of Reynolds and Schmidt numbers. Therefore, in this work, a quasi-incompressible formulation is presented for such flows wherein weak compressibility effects exist, but Mach numbers are very small. This novel approach is tested extensively in the classical lock-exchange setup where the effects of Reynolds and Schmidt numbers are analyzed. The role of density ratios is also investigated to realize whether the quasi-incompressible formulation generates a different mixing behavior or is similar to the conventional incompressible approach. The results demonstrate the convincing differences in these two formulations subjected to the specific combinations of Reynolds number, Schmidt number, and density ratio. A lenient criterion is also suggested by investigating the numerical tests carried out in this work, which may predict the possibilities of generating consistent results in both formulations.

A novel model-based Cauchy-Schwarz divergence condition indicator for gears monitoring during fluctuating speed conditions

Gear monitoring and fault diagnosis are vital for preventing accidents and minimizing economic losses in transportation and industrial systems. Traditional methods use vibration sensors and a two-stage analysis approach: preprocessing data to remove noise and extract relevant components, and generating a condition indicator to detect behavioral anomalies in the gears over time.Time synchronous averaging is a notable tool for monitoring gears at constant speeds. Such a tool filters sensor signals and extracts rotation-related components by using statistical measurements as condition indicators. However, it has limitations in scenarios with time-varying sampling rates and fluctuating speeds, where statistical measures may not fully capture changes in system parameters.This article proposes a novel methodology for monitoring gears in multivariate rotordynamical systems under fluctuating speed conditions. The method integrates time synchronous averaging, system identification algorithms, and statistical tools. It generates a time-synchronous average signal considering speed fluctuations, computes a state–space model of gear behavior in healthy states, extracts residual data from a data-driven model, and generates a condition indicator based on the Cauchy–Schwarz divergence.The proposed methodology was evaluated using experimental data from three rotor dynamical setups under different operational conditions. Validation showed its effectiveness, especially under high-load conditions with significant speed fluctuations.

Genome-wide relaxation of selection and the evolution of the island syndrome in Orkney voles.

Island populations often experience different ecological and demographic conditions than their counterparts on the continent, resulting in divergent evolutionary forces affecting their genomes. Random genetic drift and selection both may leave their imprints on island populations, although the relative impact depends strongly on the specific conditions. Here we address their contributions to the island syndrome in a rodent with an unusually clear history of isolation. Common voles (Microtus arvalis) were introduced by humans on the Orkney archipelago north of Scotland >5000 years ago and rapidly evolved to exceptionally large size. Our analyses show that the genomes of Orkney voles were dominated by genetic drift, with extremely low diversity, variable Tajima's D, and very high divergence from continental conspecifics. Increased d N/d S ratios over a wide range of genes in Orkney voles indicated genome-wide relaxation of purifying selection. We found evidence of hard sweeps on key genes of the lipid metabolism pathway only in continental voles. The marked increase of body size in Orkney-a typical phenomenon of the island syndrome-may thus be associated to the relaxation of positive selection on genes related to this pathway. On the other hand, a hard sweep on immune genes of Orkney voles likely reflects the divergent ecological conditions and possibly the history of human introduction. The long-term isolated Orkney voles show that adaptive changes may still impact the evolutionary trajectories of such populations despite the pervasive consequences of genetic drift at the genome level.

Women and Ethnic Minority Candidates Face Dynamic Party Divergent Glass Cliff Conditions in French Elections

Women and Ethnic Minority Candidates Face Dynamic Party Divergent Glass Cliff Conditions in French Elections

Analysis on characteristics of extreme precipitation indices and atmospheric circulation in Northern Shanxi

This article utilizes daily precipitation data from 28 national meteorological stations in northern Shanxi Province spanning from 1972 to 2020, and the US NCEP/NCAR monthly average reanalysis and ERA5 monthly average reanalysis data. The study employs techniques such as empirical orthogonal function (EOF) decomposition, Mann-Kendall mutation and other methods to investigate the spatiotemporal distribution of extreme precipitation index in northern Shanxi and their correlation with atmospheric circulation. The research results show that: the absolute index, relative index, intensity index and sustained dry period index (CDD) in the continuous index appear from southwest to northeast. The spatial distribution characteristics of the central region decrease, while the continuous wet period (CWD) decreases from the central to the east and west. The three indices Rx1day, Rx5day, and CWD mutated in 1978, 1975, and 1983 respectively, and other extreme precipitation indices all appeared in a sudden change from a low-value period to a high-value period occurred around 2010. In the high-value years of the summer extreme precipitation index, there is a significant negative anomaly in the height field in the mid-high latitude regions of Eurasia. Northern Shanxi is controlled by a broad low-pressure trough in the Lake Baikal area. Water vapor transported via the east, west, and south routes converges in the northern Shanxi region and encounters cold air from the north. There is a strong upward motion anomaly at 500 hPa in the troposphere, and the dynamic conditions of upper-level divergence and lower-level convergence lead to more summer extreme precipitation in the northern Shanxi region. Conversely, in the low-value years of the summer extreme precipitation index, northern Shanxi is affected by a strong high-pressure ridge north of Lake Baikal. There is a downward motion anomaly at 500 hPa, and the northern Shanxi region lacks water vapor. The cold and warm air cannot converge, and both the water vapor conditions and dynamic conditions are poor, which is not conducive to the production of extreme precipitation in northern Shanxi.

Impact of chronic muscle use and disuse on innate immune signaling in skeletal muscle

Mitochondria exhibit high levels of adaptability to various stimuli such as chronic muscle use (i.e. exercise) or disuse, such as immobilization or denervation. These changes in the mitochondrial network ultimately affect the health and functioning of skeletal muscle, which contributes to whole-body metabolism, locomotion, and postural stability. It is now acknowledged that mitochondrial dysfunction can activate inflammatory pathways through the recognition of damage-associated molecular patterns (DAMPs). The objective of this study was to examine how changes in mitochondria brought about by either chronic muscle inactivity or chronic exercise training affect innate immune system activation. We hypothesized that an inverse relationship between mitochondrial content and innate immune signaling would be evident in skeletal muscle. To investigate this, skeletal muscle from the hindlimbs of mice was collected after 7 days of sciatic muscle denervation, or after 4.5 weeks of endurance swim training involving 240 minutes of daily exercise. We analyzed the expression of the NLRP3 inflammasome, innate immune system signaling proteins, mitochondrial markers, and mitochondrial DNA (mtDNA) content using western blotting, cytochrome C oxidase (COX) activity, ELISA and qPCR. Following 7 days of denervation, there was a significant decrease in both COX-IV protein and COX activity, indicating a reduction in mitochondrial content. This was accompanied by an increase (p<0.05) in NLRP3, procaspase-1, gasdermin-D (GSDMD) and its active N-terminal fragment, GSDMD-N, as well as a notable increase in IL-1β. In addition, other possible converging pathways were also upregulated including cGAS-STING, and gasdermin-E. In comparison, following exercise training, there was a significant increase in mitochondrial content, apparent through increases in COX-IV protein, COX activity and mitochondrial RNA content. This was associated with decreases in procaspase-1 and caspase-1 protein expression alongside reduced STING activation. These findings highlight an inverse relationship between mitochondrial content and the activation of several inflammatory pathways that possibly converge upon NLRP3 inflammasome activation and pyroptotic cell death, leading to detriments in skeletal muscle health. This work aims to further the understanding of innate immune signaling pathways within muscle which can potentially highlight therapeutic targets to regulate its activation under divergent metabolic conditions. This work was supported by funds from the Natural Science and Engineering Research Council (NSERC). Priyanka Khemraj is the holder of an Ontario Graduate Scholarship. David A. Hood is the holder of a Canadian Research Chair in Cell Physiology. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Enhancing environmental DNA metabarcoding from marine ecosystems: Impact of filter type, storage method, and storage time on the assessment of fish alpha and beta diversity

AbstractThe collection of environmental DNA (eDNA) and subsequent metabarcoding are useful tools for assessing marine fish biodiversity noninvasively. It is of particular importance to evaluate biodiversity in regions that are hard to access and thus less well studied. Sampling and preservation methods tailored to the specific circumstances are required. Aquatic eDNA is often captured on filters made of different materials and pore sizes, and subsequently stored under divergent conditions for varying periods of time. Previous studies on multispecies detection in marine systems have primarily focused on capture and extraction effects. Our study, in contrast, examined the effects of filter type, storage method, and storage time on DNA yield, alpha (i.e., ZOTU richness) and beta diversity (i.e., ZOTU composition) recovered from a marine ecosystem in Shark Bay, Western Australia. We compared two different filter types (cellulose‐nitrate filters with pore sizes of 0.45 μm; glass‐fiber filters with pore sizes of 0.1 μm), two storage methods (preservation in Longmire's solution and drying, respectively), various storage times (30–68 days) on two metabarcoding assays using different fish‐specific primers. Our results showed that storage time decreased DNA yield and affected alpha and beta diversity estimates. Cellulose‐nitrate filters stored in Longmire's solution proved to be the best combination with the smallest decrease in DNA yield, no effect on alpha diversity and consistent community compositions. Storing glass‐fiber filters in Longmire's solution led to a decrease in eDNA yield and alpha diversity estimates with increasing storage time. Furthermore, the largest change in beta diversity for each metabarcode was found for glass‐fiber filters regardless of storage method. Our results highlight the importance of considering storage time and interactions between storage method and filter when analyzing eDNA results, especially when storing samples for an extended time period or comparison of samples stored for different durations.

Surface insulation performance of atmospheric and fluorinated insulating gases at highly divergent electric field conditions

Surface insulation performance of atmospheric and fluorinated insulating gases at highly divergent electric field conditions

Combining magneto-hydrostatic constraints with Stokes profile inversions. IV. Imposing divB =0 condition

Inferences of the magnetic field in the solar atmosphere by means of spectropolarimetric inversions (i.e., Stokes inversion codes) yield magnetic fields that are non-solenoidal ($ B 0$). Because of this, results obtained by such methods are sometimes put into question. We aim to develop and implement a new technique that, in conjunction with Stokes inversion codes, can retrieve magnetic fields that are simultaneously consistent with observed polarization signals and with the null divergence condition. The method used in this work strictly imposes $ B =0$ by determining the vertical component of the magnetic field ($B_ z $) from the horizontal ones ($B_ x B_ y $). We implement this technique, which we refer to as solenoidal inversion, into the FIRTEZ Stokes inversion code and apply it to spectropolarimetric observations of a sunspot observed with the Hinode/SP instrument. We show that the solenoidal inversion retrieves a vertical component of the magnetic field that is consistent in 80<!PCT!> of the analyzed three-dimensional $(x,y,z )$ domain, with the vertical component of the magnetic field inferred from the non-solenoidal inversion. We demonstrate that the solenoidal inversion is capable of a better overall fitting to the observed Stokes vector than the non-solenoidal inversion. In fact, the solenoidal magnetic field fits Stokes $V$ worse, but this is compensated by a better fit to Stokes $I$. We find a direct correlation between the worsening in the fit to the circular polarization profiles by the solenoidal inversion and the deviations in the inferred $B_ z $ with respect to the non-solenoidal inversion. Finally, we also show that the spatial distribution of the electric currents given by $ B $ does not change significantly after imposing the null divergence condition. In spite of being physically preferable, solenoidal magnetic fields are topologically very similar in 80<!PCT!> of the analyzed three-dimensional domain to the non-solenoidal fields obtained from spectropolarimetric inversions. These results support the idea that common Stokes inversion techniques fail to reproduce $ B =0$ mainly as a consequence of the uncertainties in the determination of the individual components of the magnetic field. In the remaining 20<!PCT!> of the analyzed domain, where the $B_ z $ inferred by the solenoidal and non-solenoidal inversions disagree, it remains to be proven that the solenoidal inversion is to be preferred because even though the overall fit to the Stokes parameters improves, the fit to Stokes $V$ worsens. It is in these regions where the application of the Stokes inversion constrained by the null divergence condition can yield new insights about the topology of the magnetic field in the solar photosphere.

Divergent Nitrogen, Phosphorus, and Carbon Concentrations among Growth Forms, Plant Organs, and Soils across Three Different Desert Ecosystems

Quantifying the dryland patterns of plant carbon (C), nitrogen (N), and phosphorus (P) concentrations and their stoichiometric values along environmental gradients is crucial for understanding ecological strategies. To understand the plant adaptive strategies and ecosystem nutrient concentrations across three desert ecosystems (e.g., desert, steppe desert, and temperate desert), we compiled a dataset consisting of 1295 plant species across three desert ecosystems. We assessed the element concentrations and ratios across plant growth forms, plant organs, and soils and further analysed the leaf vs. root N, P, and N:P scaling relationships. We found that the leaf N, P, and C concentrations were significantly different only from those of certain other growth forms and in certain desert ecosystems, challenging the generality of such differences. In leaves, the C concentrations were always greater than the N and P concentrations and were greater than those in soils depending on the soil chemistry and plant physiology. Thus, the element concentrations and ratios were greater in the organs than in the soils. The values in the leaf versus the root N, P, and N:P scaling relationships differed across the three desert ecosystems; for example, αN (1.16) was greater in the desert, αP (1.10) was greater in the temperate desert ecosystem, and αN:P (2.11) was greater in the desert ecosystem. The mean annual precipitation (MAP) and mean annual temperature (MAT) did not have significant effects on the leaf elemental concentrations or ratios across the desert ecosystems. This study advances our understanding of plant growth forms and organs, which support resource-related adaptive strategies that maintain the stability of desert ecosystems via divergent element concentrations and environmental conditions.

Developing Sex: From Recremental Semen to Developmental Endocrinology.

During the 1890s, animal development became associated with glandular activity, with profound implications for pediatric nosology and treatment. The significance of this endocrinological turn of developmental physiology and pathophysiology in part hinges on an often-overlooked continuity with ubiquitous early modern medical thought concerning semen as a recrementitious (reabsorbed) nutrient or stimulant. Mid-19th-century interests in adult sexual physiology were increasingly nerve-centered and antihumoral. Scattered empirical, particularly veterinarian, interests in gonadal developmental functions failed to moderate these explanatory trends. While Brown-Séquard's rejuvenation experiments still offered no clear starting point for a developmental endocrinology, in 1892 Gaston Variot and Paul Bezançon more explicitly deduced a testicular developmental endocrinological function from various observations on testicular ectopy and a local form of animal "demi-castration." Ensuing interest in thethyroid, thethymus and in thetesticles led to various working conceptions of their respective and putatively reciprocal developmental properties, including the idea of a thyroid-testis axis. From 1896, the pubertal affliction of chlorosis became the subject of multiple opotherapeutic approaches, providing an experimental basis for theories of ovarian internal secretion. Polyglandular therapy, piloted for divergent developmental conditions, remained routine until the 1930s despite the biological inefficacy of many endocrine products.

Three-dimensional magnetotelluric modeling with nontrivial anisotropy by a regularization approach

The regularization approach has been successfully applied to remove spurious solutions in the magnetotelluric (MT) forward problems of isotropic Earth media. However, spurious modes are more likely to occur in numerical solutions of anisotropic media, as electrical anisotropy introduces many more complications to electromagnetic (EM) induction in such media. This study focuses on developing the regularization approach to 3D MT forward problems of anisotropic media, especially those of nontrivial anisotropy. The governing equation is now derived with a conductivity tensor, and an accordingly adapted form of a scaled grad-div term is augmented to regularize the solutions and constrain the divergence-free condition. A new scaling scheme is proposed to cope with the complicated distribution of current densities in nontrivial anisotropy media, and an effective conductivity is approximated by the diagonal elements of the conductivity tensor to formulate the scaling factor. Numerical tests show that, for various models of electrical anisotropy, the regularization approach can effectively enforce the divergence condition and successfully suppress spurious solutions. Therefore, for nontrivial anisotropy media, this approach can also improve the efficiency of the iterative solvers while retaining the accuracy of the solutions. The derivation of the governing equation is based on the MT method. However, this strategy should be generally applicable to other frequency-domain EM methods.