Find research datasets worth reusing

opencc-zeroNov 2023View details →

Data from: A dynamical model of growth and maturation in Drosophila

The decision to stop growing and mature into an adult is a critical point in development that determines adult body size, impacting multiple aspects of an adult's biology. In many animals, growth-cessation is a consequence of hormone release that appears to be tied to attainment of particular body size or condition. Nevertheless, the size-sensing mechanism animals use to initiate hormone synthesis is poorly understood. Here we develop a simple mathematical model of growth cessation in Drosophila melanogaster, which is ostensibly triggered by attainment of a critical weight early in the last instar. Attainment of critical weight is correlated with synthesis of the steroid hormone ecdysone, which causes a larva to stop growing, pupate and metamorphose into the adult form. Our model suggests that, contrary to expectation, the size-sensing mechanism that initiates metamorphosis occurs before the larva reaches critical weight; that is, the critical-weight phenomenon is a downstream consequence of an earlier size-dependent developmental decision, not a decision point itself. Further, this size-sensing mechanism does not require a direct assessment of body size, but emerges from the interactions between body size, ecdysone and nutritional signaling. Because many aspects of our model are evolutionarily conserved among all animals, the model may provide a general framework for understanding how animals commit to maturing from their juvenile to adult form.

opencc-by-4.0Dec 2024View details →

Strategic Roadmap Toward I4.0: A Model Based on Maturity and Readiness Analysis

Modern distributed manufacturing is having an essential role in the world economy. Agility, flexibility, and responsiveness distinguishs an innovation-driven business ecosystem, mainly anchored in cloud-based environments. Therefore, manufacturing firms demand an structured roadmap to lead their way toward Industry 4.0, impacting their supply chains, operations, and business models. Naturally, dificulties will raise strong dpending how far they are from a modern ditributed model adherent to I4.0 and their readiness to start a digital transformation roadmap. Therefore, maturity and readiness analysis is essential to evaluate the impact of a sound design process toward I4.0 and to anticipate obstacles and possible return. This work proposes a design framework based on a web-based distributed cloud manufacturing approach to suport a roadmap to I4.0, relying on maturity and readiness analysis, focusing on specific building blocks as rationales.

Figure 5 in Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

Figure 5. Comparison of humerus length at birth (Lbirth), asymptotic length (AL), age at which sexual maturity is reached (ASM), and onset of maturation for pachypleurosaurs with a modeled growth record. Onset of maturation within life is estimated as ratio of the age at which sexual maturity is reached and asymptotic age (ASM / AA). It is also assessed as ratio of the age at which sexual maturity is reached and age at death (ASM / AD). White = Lbirth, black = AL, blue = ASM, red = ASM / AA, and brown = ASM / AD. High within-taxon variability in traits could suggest a sexual dimorphism in size and maturation in pachypleurosaur taxa. For values of life-history traits of specimens refer to Table 2, and for ratios to Table 3.

Figure 4 in Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

Figure 4. Allometric comparison of different life-history traits of pachypleurosaurs and Simosaurus to extant reptiles. (a) Mass at birth vs. body mass, (b) age at which sexual maturity is reached vs. body mass, (c) longevity vs. body mass, and (d) maximum growth rates vs. body mass. In all panels black triangles mark extant reptile species, red symbols pachypleurosaurs, and black crosses the nothosaur genus Simosaurus (values taken from Klein and Griebeler, 2016). Red squares = Dactylosaurus, circles = Anarosaurus, triangles = aff. N. pusillus, triangle with cross = N. pusillus, asterisk = N. edwardsii, and diamond = Serpianosaurus. Ordinary least squares regression lines and 95 % prediction intervals are shown for extant species. Varanus niloticus (grey triangle) is highlighted because it is only somewhat larger than the pachypleurosaurs studied here. Data on body mass, mass at birth (N = 782), age at which sexual maturity is reached (N = 411), and longevity (N = 1014) of extant squamates are compiled from Scharf et al. (2015). Data on body mass and maximum growth rate of reptiles (squamates, crocodiles, and turtles, N = 66) are taken from Werner and Griebeler (2014). Masses at birth of pachypleurosaurs (and Simosaurus) are larger than expected from the 95 % prediction interval for a similar-sized squamate, whereas pachypleurosaurs longevities and maximum growth rates (including that of Simosaurus) almost fit within the respective intervals. The majority of pachypleurosaurs reach sexual maturity earlier than expected for a similar-sized squamate. Overall, pachypleurosaurs (and Simosaurus) have a considerably higher mass at birth and they clearly mature earlier than a similar-sized squamate.

Figure 3 in Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

Figure 3. Growth record and established growth models for pachypleurosaurs. The statistically best growth models are shown for each specimen. These have the highest Akaike weights (Burnham and Anderson, 2002) compared to the others which were also applicable to the growth record of the specific specimen (see Table S1). Specimens are marked by colors. Growth curves on the same specimen are marked by different line types (solid, dotted) in equal color. Parameter values of models and fitting statistics are summarized in Table S1. Neusticosaurus pusillus specimens SMNS 92125 and SMNS 50372c are from the Germanic Basin (aff. N. pusillus), and specimens PIMUZ T 4178 and PIMUZ T 4211 are from the Alpine Triassic.

Figure 2 in Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

Figure 2. Growth record in Dactylosaurus from the Germanic Basin (Lower Muschelkalk, early Anisian), in aff. N. pusillus from the Germanic Basin (Lower Keuper, late Ladinian) and in Neusticosaurus spp. and in Serpianosaurus from the Alpine Triassic (Anisian/Ladinian). (a) aff. N. pusillus SMNS 92125. (b) N. pusillus PIMUZ T 4211. (c) aff. N. pusillus SMNS 50372c. (d) Dactylosaurus MB.R.786. (e) Dactylosaurus MB.R. 776.2. (f) N. edwardsii PIMUZ T4758. (g) Serpianosaurus PIMUZ T 4510. (h) Wijk 09-472. Abbreviations: sc, subcycles; sm, sexual maturity. Panels (a, b, d, e) are in normal light, (c, h) are in polarized light, and (f, g) are in polarized light with gypsum filter (lambda). Scale bar is 0.5 mm.

Figure 1 in Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

Figure 1. Details of medulla, bone tissue, and vascularization of Dactylosaurus from the early Anisian (Lower Muschelkalk; Germanic Basin) and aff. N. pusillus from the late Ladinian (Lower Keuper; Germanic Basin). (a) Medullary region distally to midshaft in Dactylosaurus humerus MB.R. 801.2. consisting of small round erosion cavities surrounded by endosteal bone and embedded in a matrix of calcified cartilage. The medullary region is surrounded by a sharp line (arrow). (b) Medullary region closer to midshaft in Dactylosaurus humerus MB.R. 771.5 displaying a small free cavity, a few small erosion cavities surrounded by endosteal bone and calcified cartilage at the border to the periosteal region all encompassed by a sharp line (arrow). Around the medullary cavity slow-deposited (i.e., highly organized) hatchling bone tissue is visible. (c) The medullary region and inner cortex in aff. N. pusillus humerus SMNS 50372b is nearly completely filled by endosteal bone. The area is surrounded by the sharp line (arrow), although the sample was taken nearly at the midshaft. Scattered longitudinal primary osteons occur in this sample. (d) Cross section of aff. N. pusillus humerus SMNS 58025a which shows an irregular medullary region and remodeling in form of erosion cavities scattered into the periosteal bone. (e) Medullary region and inner cortex of aff. N. pusillus humerus SMNS 50372c. The medullary region consists of few small erosion cavities and endosteal bone. The innermost cortex is made of fast-deposited hatchling bone tissue, which is surrounded by a distinct annulus. (f) Medullary region and inner cortex of aff. N. pusillus humerus SMNS 92125. The medullary region consists of a small cavity surrounded by a thick layer of endosteal bone, which are encompassed by a sharp line and calcified cartilage. The innermost cortex is made of a slow-deposited hatchling bone tissue. (g) Cross section of N. pusillus humerus PIMUZ T 3975. The medullary region is completely filled by endosteal bone. The area is surrounded by some erosion cavities. (h) Medullary region and inner cortex at midshaft in Dactylosaurus humerus MB.R. 776.2 showing a free cavity surrounded by a thick layer of endosteal bone. On the right side are remains of preserved fast-deposited (i.e., less organized) hatchling bone tissue. On the right side, the layer of horizontally oriented fine fibers is visible (arrow). (i) Medullary region and inner cortex in Anarosaurus humerus Wijk 13-194. The relatively large, free medullary cavity is surrounded by a thin, and in this sample incomplete, layer of endosteal bone. The innermost cortex is made of a fast-deposited (i.e., highly organized) hatchling bone tissue, which is surrounded by a distinct annulus. A second annulus is clearly visible in the lower part of the picture. Distance between annuli changes considerably towards the preaxial bone side (arrows mark spilt). Abbreviations: cc, calcified cartilage; eb, endosteal bone; ec, erosion cavity; htb, hatchling bone tissue; ffho, fine fibers horizontally oriented; mc, medullary cavity; mr, medullary region; po, primary osteon. All pictures are in polarized light. Scale bar is 0.5 mm if not labeled otherwise.

opencc-by-4.0Oct 2024View details →

Real-time monitoring of a 3D blood-brain barrier model maturation and integrity with a sensorized microfluidic device

A significant challenge in the treatment of central nervous system (CNS) disorders is represented by the presence of the blood-brain barrier (BBB), a highly selective membrane that regulates molecular transport and restricts the passage of pathogens and therapeutic compounds. Traditional in vivo models are constrained by high costs, lengthy experimental timelines, ethical concerns, and interspecies variations. In vitro models, particularly microfluidic BBB-on-a-chip devices, have been developed to address these limitations. These advanced models aim to more accurately replicate human BBB conditions by incorporating human cells and physiological flow dynamics. In this framework, here we developed an innovative microfluidic system that integrates thin-film electrodes for non-invasive, real-time monitoring of BBB integrity using electrochemical impedance spectroscopy (EIS). EIS measurements showed frequency-dependent impedance changes, indicating BBB integrity and distinguishing well-formed from non-mature barriers. The data from EIS monitoring was confirmed by permeability assays performed with a fluorescence tracer. The model incorporates human endothelial cells in a vessel-like arrangement to mimic the vascular component and three-dimensional cell distribution of human astrocytes and microglia to simulate the parenchymal compartment. By modeling the BBB-on-a-chip with an equivalent circuit, a more accurate trans-endothelial electrical resistance (TEER) value was extracted. The device demonstrated successful BBB formation and maturation, confirmed through live/dead assays, immunofluorescence and permeability assays. Computational fluid dynamics (CFD) simulations confirmed that the device mimics in vivo shear stress conditions. Drug crossing assessment was performed with two chemotherapy drugs: doxorubicin, with a known poor BBB penetration, and temozolomide, conversely specific drug for CNS disorders and able to cross the BBB, to validate the model predictive capability for drug crossing behavior. The proposed sensorized microfluidic device represents a significant advancement in BBB modeling, offering a versatile platform for CNS drug development, disease modeling, and personalized medicine.

opencc-zeroMar 2023View details →

Data for: Predicting age and mass at maturity from feeding behavior and diet in M. sexta: An empirical test of a life history model

Feeding for most animals involves bouts of active ingestion alternating with bouts of no ingestion. In insects, the temporal patterning of bouts varies widely with resource quality and is known to affect growth, development time, and fitness. However, the precise impacts of resource quality and feeding behavior on insect life history traits is poorly understood. To explore and better understand the connections between feeding behavior, resource quality and insect life history traits, we combined laboratory experiments with a recently proposed mechanistic model of insect growth and development for a larval herbivore, Manduca sexta. We ran feeding trials for 4th and 5th instar larvae across different diet types (two hostplants and artificial diet) and used these data to parameterize a joint model of age and mass at maturity that incorporates both insect feeding behavior and hormonal activity. We found that the estimated durations of both feeding and non-feeding bouts were significantly shorter on low- than on high-quality diets. We then explored how well the fitted model predicted historical out-of-sample data on age and mass of M. sexta. We found that the model accurately described qualitative outcomes for the out-of-sample data, notably that a low-quality diet results in reduced mass and later age at maturity compared to high-quality diets. Our results clearly demonstrate the importance of diet quality on multiple components of insect feeding behavior (feeding and non-feeding), and partially validate a joint model of insect life history. We discuss the implications of these findings with respect to insect herbivory and discuss ways in which our model could be improved or extended to other systems.

publicMar 2023View details →

Data for: Predicting age and mass at maturity from feeding behavior and diet in M. sexta: An empirical test of a life history model

Open the record for dataset details and reuse information.