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We interpret a newly discovered laminated limestone associated with Middle Proterozoic rocks in the Redrock and Brushy Mountain quadrangles of southwestern New Mexico as representing stromatolites, possibly Conophyton. This locality is geographically aligned with other outcrops of ~1.2 Ga stromatolites documented in the southwest U.S., such as those in the Bass Formation (Grand Canyon, AZ), the Mescal Limestone (Salt River Canyon, AZ), the Castner Marble (Franklin Mountains, TX), and the Allamoore Formation (Van Horn, TX). These stromatolites have similar morphologies to those found in Texas and represent the first instance of Proterozoic fossils identified within the state of New Mexico. The stromatolite-bearing unit, termed here the Ash Creek Limestone, is exposed along with a marble unit surrounded by the ~1225 Ma Redrock Granite (Williams, 2015). Mapping at 1:6,000 scale shows that the carbonates are also associated with a unit consisting of serpentinite interbedded with talc (forming a rock informally referred to as ricolite), meaning they share a similar depositional setting. The carbonates are only found surrounded by granite, whereas ricolite outcrops are typically in contact with a metabasalt. The metabasalt yielded a U-Pb zircon weighted mean 207Pb/206Pb age of 1229 ± 12 Ma (n= 35; MSWD= 0.8). This represents the first direct dating of ~1.2 Ga mafic volcanism in the area, and these racks are similar in age to anorthosite dated at 1223 ± 6 Ma and 1231 ± 4 Ma (Ramo et al., 2003). Together, the ~1.2 Ga bimodal magmatism and shallow marine limestone units indicate that the tectonic setting of southwest Laurentia at this time involved a NW-SE-trending Mesoproterozoic seaway that formed as a result of coeval regional extension during the early stages of the Grenville orogeny. 

This paper presents the design, development, and testing of a robot that combines soft-body grasping and crawling locomotion to navigate tubular objects. Inspired by the natural snakes’ climbing locomotion of tubular objects, the soft robot includes proximal and distal modules with radial expansion/contraction for grasping around the objects and a longitudinal contractile–expandable driving module in-between for providing a bi-directional crawling movement along the length of the object. The robot’s grasping modules are made of fabrics, and the crawling module is made of an extensible pneumatic soft actuator (ePSA). Conceptual designs and CAD models of the robot parts, textile-based inflatable structures, and pneumatic driving mechanisms were developed. The mechanical parts were fabricated using advanced and conventional manufacturing techniques. An Arduino-based electro-pneumatic control board was developed for generating cyclic patterns of grasping and locomotion. Different reinforcing patterns and materials characterize the locomotor actuators’ dynamical responses to the varying input pressures. The robot was tested in a laboratory setting to navigate a cable, and the collected data were used to modify the designs and control software and hardware. The capability of the soft robot for navigating cables in vertical, horizontal, and curved path scenarios was successfully demonstrated. Compared to the initial design, the forward speed is improved three-fold. 

T cells are required to clear infection, and T cell motion plays a role in how quickly a T cell finds its target, from initial naive T cell activation by a dendritic cell to interaction with target cells in infected tissue. To better understand how different tissue environments affect T cell motility, we compared multiple features of T cell motion including speed, persistence, turning angle, directionality, and confinement of T cells moving in multiple murine tissues using microscopy. We quantitatively analyzed naive T cell motility within the lymph node and compared motility parameters with activated CD8 T cells moving within the villi of small intestine and lung under different activation conditions. Our motility analysis found that while the speeds and the overall displacement of T cells vary within all tissues analyzed, T cells in all tissues tended to persist at the same speed. Interestingly, we found that T cells in the lung show a marked population of T cells turning at close to 180^o, while T cells in lymph nodes and villi do not exhibit this “reversing” movement. T cells in the lung also showed significantly decreased meandering ratios and increased confinement compared to T cells in lymph nodes and villi. These differences in motility patterns led to a decrease in the total volume scanned by T cells in lung compared to T cells in lymph node and villi. These results suggest that the tissue environment in which T cells move can impact the type of motility and ultimately, the efficiency of T cell search for target cells within specialized tissues such as the lung.

 

Two lytic phages infectingGordonia rubripertinctawere isolated from irrigated desert soil. Phage LilyPad and PokyPuppy have 64,158-bp and 77,065-bp genomes, respectively. Based on gene content similarity to phages in the Actinobacteriophage database, LilyPad is assigned to phage subcluster DG1 and PokyPuppy to subcluster CS2. 

Ferrofluids are colloidal suspensions of iron oxide nanoparticles (IONPs) within aqueous or nonaqueous liquids that exhibit strong magnetic properties. These magnetic properties allow ferrofluids to be manipulated and controlled when exposed to magnetic fields. This review aims to provide the current scope and research opportunities regarding the methods of synthesis of nanoparticles, surfactants, and carrier liquids for ferrofluid production, along with the rheology and applications of ferrofluids within the fields of medicine, water treatment, and mechanical engineering. A ferrofluid is composed of IONPs, a surfactant that coats the magnetic IONPs to prevent agglomeration, and a carrier liquid that suspends the IONPs. Coprecipitation and thermal decomposition are the main methods used for the synthesis of IONPs. Despite the fact that thermal decomposition provides precise control on the nanoparticle size, coprecipitation is the most used method, even when the oxidation of iron can occur. This oxidation alters the ratio of maghemite/magnetite, influencing the magnetic properties of ferrofluids. Strategies to overcome iron oxidation have been proposed, such as the use of an inert atmosphere, adjusting the Fe(II) and Fe(III) ratio to 1:2, and the exploration of other metals with the oxidation state +2. Surfactants and carrier liquids are chosen according to the ferrofluid application to ensure stability. Hence, a compatible carrier liquid (polar or nonpolar) is selected, and then, a surfactant, mainly a polymer, is embedded in the IONPs, providing a steric barrier. Due to the variety of surfactants and carrier liquids, the rheological properties of ferrofluids are an important response variable evaluated when synthesizing ferrofluids. There are many reported applications of ferrofluids, including biosensing, medical imaging, medicinal therapy, magnetic nanoemulsions, and magnetic impedance. Other applications include water treatment, energy harvesting and transfer, and vibration control. To progress from synthesis to applications, research is still ongoing to ensure control of the ferrofluids’ properties. 

This research paper investigates the relationship between race/ ethnicity, gender, first-generation college student status, and engineering identity using cross-sectional data from early-career engineering majors. Measures of engineering identity are increasingly used in models of engineering education to evaluate how identity contributes to success and persistence of engineering students. Engineering identity is generally assumed to contribute to educational success, with stronger engineering identity leading to persistence. At the same time, data clearly shows that persistence of engineering students varies by race/ethnicity and gender. Given these previous findings, we would expect to find that engineering identity will vary by race/ ethnicity, gender, and first generation status. Yet, relatively little work has quantitatively compared how engineering identity differs across racial/ ethnic groups and gender. While researchers are increasingly trying to gain a better understanding of engineering identity among Latina students, for example, the literature has not yet adequately accounted for how Latina students differ from their non-Hispanic white peers. This works seeks to address that gap in the literature with an exploration of the ways that race/ethnicity, gender, and first generation status work together to impact engineering identity among early-career engineering students at four public Hispanic-Serving Institutions (HSIs) in the Southwestern United States. We conducted surveys as part of a longitudinal study on STEM education. Data discussed here comes from baseline surveys of three cohorts of engineering students (N=475). Approximately two-thirds of the respondents were attending a traditional 4-year university while the remainder (N=159) were attending community college at the time of the survey. Approximately two-thirds of the respondents identified as Latinx, 27% identified as female, and 26.5% reported that they were first-generation college students. While expectations were that engineering identity would vary by race/ethnicity and gender, preliminary analyses of our data unexpectedly reveal no significant differences between Latinx and White students in terms of their engineering identity and no significant differences in engineering identity between male and female students. Interactions between race/ethnicity and gender were also tested and yielded no significant differences between early-career Latinx and White students in terms of their engineering identity. Finally, students who reported that they will be the first in their family to get a college degree had significantly lower engineering identity scores (=-.422; p=.001). These results lead us to conclude that first generation status at HSIs may be more important than gender and race/ ethnicity in the development of engineering identity for early career students.