Does \u3cem\u3eRubus canadensis\u3c/em\u3e Interfere with the Growth of Fraser Fir Seedlings?

Vegetation change in the Great Smoky Mountains following balsam woolly adelgid-caused mortality of Fraser fir has included development of a dense Rubus canadensis shrub layer. Many fir seedlings have persisted in the forest understory, but the possible effects of Rubus on their annul growth have not been intensively studied. This study had two objectives: (1) to determine if significant associations exist among density and shoot growth of Fraser fir seedling, density/biomass of Rubus canadensis, canopy closure, and soil chemical parameters, and (2) to determine the effects of removal of aboveground Rubus stems on fir seedling shoot growth. Eighty 1 x 1 m plots were used on Mount Collins, Great Smoky Mountains National Park, to characterize the understory habitat of Fraser fir seedlings. Terminal and lateral shoot lengths of the 1983-1987 growth were measured on fir seedlings. Seedlings were classified according to substrate type, surface type, substrate form, presence of adelgid damage, and age. Soil samples were taken for analyses of pH, potassium, phosphorus, and calcium. Overstory composition was characterized with prism plots. Fourteen 2 x 2 m plots were established to determine effects of Rubus removal on fir seedling growth, herbaceous cover, shrub/seedling counts, and soil parameters. Rubus canadensis density was highest on the southwest-facing slope and lowest on the northeast-facing slope of Mount Collins. Fraser fir seedling density was highest on theortheast-facing slope and lowest on the southwest -facing slope. The spearman rank correlation between Rubus density and fir seedling density was -0.376 (P \u3c 0.01); a graph of these data showed variability in fir density to decrease with increasing Rubus density. Most years of fir terminal shoot growth showed positive associations with Rubus density (0.309-0.396, P \u3c 0.01); a graph of these data showed no pronounced relationship. Rubus density and biomass were significantly correlated with soil phosphorus and potassium concentrations. All years of terminal shoot growth of fir seedlings measured showed positive associations with soil pH and potassium concentration. Most fir seedlings were ≤25 cm tall. Only 38% were \u3c5 years old. More seedling than expected occupied dead wood substrates, and more than expected were found on bryophyte-covered surfaces. More than 25% of seedlings showed adelgid damage; adelgid damage was more prevalent among seedlings ≥5 years old. Most seedlings showed a trend of increasing gains of terminal shoot growth over previous years of growth. Removal of Rubus stems produced no significant effect of fir seedling shoot growth over one season. No Rubus-removal effects were found on any other understory variable measured; Rubus itself responded to removal by rapid appearance and growth of new stems. Large seasonal changes in bryophyte cover and red spruce seedling density (from germination) occurred, but these changes were not affected by Rubus removal. Germinal Fraser fir seedlings are scarce and are not likely to appear in large numbers unless existing understory firs reach reproductive age. Rubus appears to inhibit the establishment of fir seedlings. Fir shoot growth does not appear to be associated with Rubus density or biomass. Fir Shoot growth trends are probably consequences of normal growth patterns and recovery from adelgid infestation

Notes on the Distribution and Natural History of the Eastern Wormsnake (Carphophis amoenus amoenus) in West Virginia

Small fossorial snakes, such as the Eastern Wormsnake (Carphophis amoenus amoenus), are often neglected in studies since they lead a fossorial life and are frequently hard to find. Since it was last studied nearly 40 years ago, we present an update on distribution, habitat preferences, and diet of the Eastern Wormsnake in West Virginia. We found that this species resides in only a fraction of its original range due to habitat destruction by industrial, residential, and commercial developments. Habitat data suggests this species can tolerate a range of soil temperatures (15–24 °C), air temperatures (23.1 degrees Celsius), and relative humidity (24.5-80%), and can be found on nearly all slope directions. Dietary analysis showed annelids make up the majority of their diet but other invertebrate prey are also taken

Program Analysis of Commodity IoT Applications for Security and Privacy: Challenges and Opportunities

Recent advances in Internet of Things (IoT) have enabled myriad domains such as smart homes, personal monitoring devices, and enhanced manufacturing. IoT is now pervasive---new applications are being used in nearly every conceivable environment, which leads to the adoption of device-based interaction and automation. However, IoT has also raised issues about the security and privacy of these digitally augmented spaces. Program analysis is crucial in identifying those issues, yet the application and scope of program analysis in IoT remains largely unexplored by the technical community. In this paper, we study privacy and security issues in IoT that require program-analysis techniques with an emphasis on identified attacks against these systems and defenses implemented so far. Based on a study of five IoT programming platforms, we identify the key insights that result from research efforts in both the program analysis and security communities and relate the efficacy of program-analysis techniques to security and privacy issues. We conclude by studying recent IoT analysis systems and exploring their implementations. Through these explorations, we highlight key challenges and opportunities in calibrating for the environments in which IoT systems will be used.Comment: syntax and grammar error are fixed, and IoT platforms are updated to match with the submissio

Measuring and Mitigating the Risk of IP Reuse on Public Clouds

Public clouds provide scalable and cost-efficient computing through resource sharing. However, moving from traditional on-premises service management to clouds introduces new challenges; failure to correctly provision, maintain, or decommission elastic services can lead to functional failure and vulnerability to attack. In this paper, we explore a broad class of attacks on clouds which we refer to as cloud squatting. In a cloud squatting attack, an adversary allocates resources in the cloud (e.g., IP addresses) and thereafter leverages latent configuration to exploit prior tenants. To measure and categorize cloud squatting we deployed a custom Internet telescope within the Amazon Web Services us-east-1 region. Using this apparatus, we deployed over 3 million servers receiving 1.5 million unique IP addresses (56% of the available pool) over 101 days beginning in March of 2021. We identified 4 classes of cloud services, 7 classes of third-party services, and DNS as sources of exploitable latent configurations. We discovered that exploitable configurations were both common and in many cases extremely dangerous; we received over 5 million cloud messages, many containing sensitive data such as financial transactions, GPS location, and PII. Within the 7 classes of third-party services, we identified dozens of exploitable software systems spanning hundreds of servers (e.g., databases, caches, mobile applications, and web services). Lastly, we identified 5446 exploitable domains spanning 231 eTLDs-including 105 in the top 10,000 and 23 in the top 1000 popular domains. Through tenant disclosures we have identified several root causes, including (a) a lack of organizational controls, (b) poor service hygiene, and (c) failure to follow best practices. We conclude with a discussion of the space of possible mitigations and describe the mitigations to be deployed by Amazon in response to this study

EIPSIM: Modeling Secure IP Address Allocation at Cloud Scale

Public clouds provide impressive capability through resource sharing. However, recent works have shown that the reuse of IP addresses can allow adversaries to exploit the latent configurations left by previous tenants. In this work, we perform a comprehensive analysis of the effect of cloud IP address allocation on exploitation of latent configuration. We first develop a statistical model of cloud tenant behavior and latent configuration based on literature and deployed systems. Through these, we analyze IP allocation policies under existing and novel threat models. Our resulting framework, EIPSim, simulates our models in representative public cloud scenarios, evaluating adversarial objectives against pool policies. In response to our stronger proposed threat model, we also propose IP scan segmentation, an IP allocation policy that protects the IP pool against adversarial scanning even when an adversary is not limited by number of cloud tenants. Our evaluation shows that IP scan segmentation reduces latent configuration exploitability by 97.1% compared to policies proposed in literature and 99.8% compared to those currently deployed by cloud providers. Finally, we evaluate our statistical assumptions by analyzing real allocation and configuration data, showing that results generalize to deployed cloud workloads. In this way, we show that principled analysis of cloud IP address allocation can lead to substantial security gains for tenants and their users

The impact of body composition on energy expenditure during walking and running in young adults

The purpose of this study was to examine the impact of body composition on energy expenditure (EE) of 164 young adults during a 1-mile walk and a 1-mile run on a treadmill. Segmental bioimpedance was used to measure body composition variables. The EE in men (108.3 ± 17.6 kcal) was greater than (P \u3c 0.05) women (80.3 ± 10.6 kcal) during the 1-mile walk, and the difference increased in magnitude during the 1-mile run (144.9 ± 23.2 kcal vs. 105.1 ± 14.9 kcal, respectively). When EE was expressed per unit of body mass, men and women were similar. However, women had a higher EE per unit of fat-free mass (FFM). Regardless of gender, running 1-mile resulted in a greater EE than walking 1-mile. In addition, men expended more absolute calories than women due to a higher body mass. When EE was examined relative to FFM, women were found to be less economical than men, which was most likely due to carrying larger amounts of inactive adipose tissue

Securing Cloud File Systems using Shielded Execution

Cloud file systems offer organizations a scalable and reliable file storage solution. However, cloud file systems have become prime targets for adversaries, and traditional designs are not equipped to protect organizations against the myriad of attacks that may be initiated by a malicious cloud provider, co-tenant, or end-client. Recently proposed designs leveraging cryptographic techniques and trusted execution environments (TEEs) still force organizations to make undesirable trade-offs, consequently leading to either security, functional, or performance limitations. In this paper, we introduce TFS, a cloud file system that leverages the security capabilities provided by TEEs to bootstrap new security protocols that meet real-world security, functional, and performance requirements. Through extensive security and performance analyses, we show that TFS can ensure stronger security guarantees while still providing practical utility and performance w.r.t. state-of-the-art systems; compared to the widely-used NFS, TFS achieves up to 2.1X speedups across micro-benchmarks and incurs <1X overhead for most macro-benchmark workloads. TFS demonstrates that organizations need not sacrifice file system security to embrace the functional and performance advantages of outsourcing