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The Ross Sea in the Southern Ocean is frequently considered one of the most pristine ecosystems in the world, but recent data suggest that changes to oceanic conditions may be impacting wildlife abundance. We used 41 yr of data to assess how variation in biologically relevant environmental conditions relates to annual reproductive output for the world’s largest population of Weddell sealsLeptonychotes weddellii, an upper-level predator in the Ross Sea. Pup production increased 150% across the time series, and interannual variation tripled. Linear regression analyses, which explained 73.7% of the variance in pup production, supported a non-linear, convex relationship between reproductive output and summer sea ice extent, with more pups born in years with more or less sea ice than in years with intermediate ice extent. While total annual toothfish catch 7 yr previous appears to be positively associated with reproductive output, a similar amount of variation in pup production could be explained by an alternative model with a linear, temporal trend. Our results highlight a sizable increase in the reproductive output of this demographically buffered polar marine predator. The increase in pup production may be the result of competitive release due to commercial fishing, cascading ecological effects from commercial fishing or other environmental shifts, or population inertia from a few large birth cohorts. It is challenging to disentangle these hypotheses with the current publicly available environmental data. Future demographic analyses and collaborative research are needed to understand how environmental changes are impacting marine populations in this ecosystem. 

Abstract BackgroundEctothermic arthropods, like ticks, are sensitive indicators of environmental changes, and their seasonality plays a critical role in the dynamics of tick-borne disease in a warming world. Juvenile tick phenology, which influences pathogen transmission, may vary across climates, with longer tick seasons in cooler climates potentially amplifying transmission. However, assessing juvenile tick phenology is challenging in arid climates because ticks spend less time seeking for blood meals (i.e. questing) due to desiccation pressures. As a result, traditional collection methods like dragging or flagging are less effective. To improve our understanding of juvenile tick seasonality across a latitudinal gradient, we examinedIxodes pacificusphenology on lizards, the primary juvenile tick host in California, and explored how climate factors influence phenological patterns. MethodsBetween 2013 and 2022, ticks were removed from 1527 lizards at 45 locations during peak tick season (March–June). Tick counts were categorized by life stage (larvae and nymphs) and linked with remotely sensed climate data, including monthly maximum temperature, specific humidity and Palmer Drought Severity Index (PDSI). Juvenile phenology metrics, including tick abundances on lizards, Julian date of peak mean abundance and temporal overlap between larval and nymphal populations, were analyzed along a latitudinal gradient. Generalized additive models (GAMs) were applied to assess climate-associated variation in juvenile abundance on lizards. ResultsMean tick abundance per lizard ranged from 0.17 to 47.21 across locations, with the highest abundance in the San Francisco Bay Area and lowest in Los Angeles, where more lizards had zero ticks attached. In the San Francisco Bay Area, peak nymphal abundance occurred 25 days earlier than peak larval abundance. Temporal overlap between larval and nymphal stages at a given location varied regionally, with northern areas showing higher overlap, possibly due to the bimodal seasonality of nymphs. We found that locations with higher temperatures and increased drought stress were linked to lower tick abundances, although the magnitude of these effects depended on regional location. ConclusionsOur study, which compiled 10 years of data, reveals significant regional variation in juvenileI. pacificusphenology across California, including differences in abundance, peak timing, and temporal overlap. These findings highlight the influence of local climate on tick seasonality, with implications for tick-borne disease dynamics in a changing climate. Graphical Abstract 

Abstract The closure of the Mozambique Ocean defines the final assembly of the megacontinent Gondwana and is associated with a vast region of crustal growth in the Arabian-Nubian Shield. Despite this central paleogeographic position, there are few constraints on the position of terranes within and bounding the Mozambique Ocean. We report paleomagnetic data from ca. 726 Ma dikes exposed in southern Oman. Well-resolved magnetite magnetization is constrained to be primary by a conglomerate test on mafic clasts within overlying Cryogenian diamictite. The resulting paleomagnetic pole indicates that Oman was at a paleolatitude of 37 ± 2.5°N and was rotated ~80° counterclockwise from its present-day orientation. This position is consistent with Oman forming a contiguous plate with the India and South China cratons on the northern margin of the Mozambique Ocean in a distinct tectonic domain from Arabian-Nubian arcs to the south. This position reveals an ~5500-km-wide oceanic realm prior to subsequent closure that resulted in a major zone of Neoproterozoic crustal growth. 

Microservices are a dominant cloud computing architecture because they enable applications to be built as collections of loosely coupled services. To provide greater observability and control into the resultant distributed system, microservices often use an overlay proxy network called a service mesh. A key advantage of service meshes is their ability to implement zero trust networking by encrypting microservice traffic with mutually authenticated TLS. However, the service mesh control plane—particularly its local certificate authority—becomes a critical point of trust. If compromised, an attacker can issue unauthorized certificates and redirect traffic to impersonating services. In this paper, we introduce our initial work in Mazu, a system designed to eliminate trust in the service mesh control plane by replacing its certificate authority with an unprivileged principal. Mazu leverages recent advances in registration-based encryption and integrates seamlessly with Istio, a widely used service mesh. Our preliminary evaluation, using Fortio macro-benchmarks and Prometheus-assisted micro-benchmarks, shows that Mazu significantly reduces the service mesh’s attack surface while adding just 0.17 ms to request latency compared to mTLS-enabled Istio.