Intermediate-grade brain arteriovenous malformations and the boundary of operability using the supplemented Spetzler-Martin grading system

OBJECTIVE Supplemented Spetzler-Martin grading (Supp-SM), which is the combination of Spetzler-Martin and Lawton-Young grades, was validated as being more accurate than stand-alone Spetzler-Martin grading, but an operability cutoff was not established. In this study, the authors surgically treated intermediate-grade AVMs to provide prognostic factors for neurological outcomes and to define AVMs at the boundary of operability. METHODS Surgically treated Supp-SM intermediate-grade (5, 6, and 7) AVMs were analyzed from 2011 to 2018 at two medical centers. Worsened neurological outcomes were defined as increased modified Rankin Scale (mRS) scores on postoperative examinations. A second analysis of 2000–2011 data for Supp-SM grade 6 and 7 AVMs was performed to determine the subtypes with improved or unchanged outcomes. Patients were separated into three groups based on nidus size (S1: < 3 cm, S2: 3–6 cm, S3: > 6 cm) and age (A1: < 20 years, A2: 20–40 years, A3: > 40 years), followed by any combination of the combined supplemented grade: low risk (S1A1, S1A2, S2A1), intermediate risk (S2A2, S1A3, S3A1, or high risk (S3A3, S3A2, S2A3). RESULTS Two hundred forty-six patients had intermediate Supp-SM grade AVMs. Of these patients, 102 had Supp-SM grade 5 (41.5%), 99 had Supp-SM grade 6 (40.2%), and 45 had Supp-SM grade 7 (18.3%). Significant differences in the proportions of patients with worse mRS scores at follow-up were found between the groups, with 24.5% (25/102) of patients in Supp-SM grade 5, 29.3% (29/99) in Supp-SM grade 6, and 57.8% (26/45) in Supp-SM grade 7 (p < 0.001). Patients with Supp-SM grade 7 AVMs had significantly increased odds of worse postoperative mRS scores (p < 0.001; OR 3.7, 95% CI 1.9–7.3). In the expanded cohort of 349 Supp-SM grade 6 AVM patients, a significantly higher proportion of older patients with larger Supp-SM grade 6 AVMs (grade 6+, 38.6%) had neurological deterioration than the others with Supp-SM grade 6 AVMs (22.9%, p = 0.02). Conversely, in an expanded cohort of 197 Supp-SM grade 7 AVM patients, a significantly lower proportion of younger patients with smaller Supp-SM grade 7 AVMs (grade 7–, 19%) had neurological deterioration than the others with Supp-SM grade 7 AVMs (44.9%, p = 0.01). CONCLUSIONS Patients with Supp-SM grade 7 AVMs are at increased risk of worse postoperative neurological outcomes, making Supp-SM grade 6 an appropriate operability cutoff. However, young patients with small niduses in the low-risk Supp-SM grade 7 group (grade 7−) have favorable postoperative outcomes. Outcomes in Supp-SM grade 7 patients did not improve with surgeon experience, indicating that the operability boundary is a hard limit reflecting the complexity of high-grade AVMs.

Hard limits to cognitive flexibility: ants can learn to ignore but not avoid pheromone trails

Learning allows animals to respond to changes in their environment within their lifespan. However, many responses to the environment are innate, and need not be learned. Depending on the level of cognitive flexibility an animal shows, such responses can either be modified by learning or not. Many ants deposit pheromone trails to resources, and innately follow such trails. Here, we investigated cognitive flexibility in the ant Lasius niger by asking whether ants can overcome their innate tendency and learn to avoid conspecific pheromone trails when these predict a negative stimulus. Ants were allowed to repeatedly visit a Y-maze, one arm of which was marked with a strong but realistic pheromone trail and led to a punishment (electroshock and/or quinine solution), and the other arm of which was unmarked and led to a 1 M sucrose reward. After circa 10 trials ants stopped relying on the pheromone trail, but even after 25 exposures they failed to improve beyond chance levels. However, the ants did not choose randomly: rather, most ants begun to favour just one side of the Y-maze, a strategy which resulted in more efficient food retrieval over time, when compared to the first visits. Even when trained in a go/no-go paradigm which precludes side bias development, ants failed to learn to avoid a pheromone trail. These results show rapid learning flexibility towards an innate social signal, but also demonstrate a rarely seen hard limit to this flexibility.

Low potential for evolutionary rescue from climate change in a tropical fish

Climate change is increasing global temperatures and intensifying the frequency and severity of extreme heat waves. How organisms will cope with these changes depends on their inherent thermal tolerance, acclimation capacity, and ability for evolutionary adaptation. Yet, the potential for adaptation of upper thermal tolerance in vertebrates is largely unknown. We artificially selected offspring from wild-caught zebrafish (Danio rerio) to increase (Up-selected) or decrease (Down-selected) upper thermal tolerance over six generations. Selection to increase upper thermal tolerance was also performed on warm-acclimated fish to test whether plasticity in the form of inducible warm tolerance also evolved. Upper thermal tolerance responded to selection in the predicted directions. However, compared to the control lines, the response was stronger in the Down-selected than in the Up-selected lines in which evolution toward higher upper thermal tolerance was slow (0.04 ± 0.008 °C per generation). Furthermore, the scope for plasticity resulting from warm acclimation decreased in the Up-selected lines. These results suggest the existence of a hard limit in upper thermal tolerance. Considering the rate at which global temperatures are increasing, the observed rates of adaptation and the possible hard limit in upper thermal tolerance suggest a low potential for evolutionary rescue in tropical fish living at the edge of their thermal limits.

Penerapan Jaringan Syaraf Tiruan Metode Hopfield Untuk Prediksi Cuaca di Kota Palangka Raya

Forecasting atau peramalan merupakan salah satu bagian dari ilmu statistika yang digunakan untuk meramalkan suatu kemungkinan yang akan terjadi dimasa yang akan datang, berdasarkan pada data masa lampau yang akan dianalisis dengan menggunakan cara-cara tertentu. pemodelan yang cocok untuk peramalan saat ini adalah bidang jaringan syaraf tiruan dan salah satu penerapannya menggunakan metode hopfield. Di peramalan prakiraan cuaca unsur-unsur cuaca merupakan faktor terpenting dalam menentukan suatu pemodelan seperti kecepatan udara, suhu udara, kelembaban udara, dan tekanan udara. Pada jaringan hopfield, neuron input yang digunakan adalah unsur-unsur cuaca tersebut yang diubah dalam bentuk fungsi bipolar threshold diproses sampai mencapai stabil/konvergen dengan fungsi aktivasi bipolar symetric hard limit. Penelitian ini menggunakan fungsi bipolar threshold yang didapat berdasarkan nilai-nilai dari keempat unsur cuaca tersebut. Sistem ini menggunakan model jaringan dengan empat neuron input yang terhubung dengan bobot-bobot lapisan yang simetris dan tiga nilai output jaringan, yaitu kriteria cerah dengan nilai [-1 1 1 1], kriteria berawan dengan nilai [0 0 0 0], dan kriteria hujan dengan nulai [1 -1 1 -1]. Penerapan metode hopfield untuk prakiraan cuaca di Wilayah Palangka Raya dengan data pagi sebanyak 78 yang terdiri dari data pagi, siang dan malam. setelah data dilakukan pengujian maka terlihat bahwa metode ini mampu memberikan akurasi sebesar 64% dan error sebesar 36%

Water quality of Barishal sadar upazila in Bangladesh for drinking, irrigation, aquaculture and livestock consumption

A study was conducted to assess of groundwater and surface water quality of Barisal sadar upazila. Total 22 water samples (11 pond water and 11 groundwater) were collected from January to March, 2017. Samples were slightly acidic in nature and 7 pond water not suitable for aquaculture in respect of pH. Samples of pond were “excellent” and groundwater samples were “good” for irrigation except two high salinity group water for irrigation for EC. Calcium indicates the samples were suitable for aquaculture but 7 samples were not suitable due to higher Mg content. In respect of K, 9 samples were not suitable for aquaculture. Cu concentrations found suitable for all purposes. For Fe and Zn samples are suitable for irrigation and consumption. Chloride showed, samples were not suitable for livestock consumption except 7 ponds sample. Samples are not suitable for aquaculture in respect of Cl, Fe and Zn. For Manganese, samples (except 1) found suitable for consumption. Samples were “excellent” for sensitive, semi-tolerant and tolerant crops in respect of B. Not any samples responded to CO3 test and HCO3 concentrations found normal. All water sources free from Arsenic contamination. Phosphorus concentration in groundwater might not be harmful for multipurpose use. SAR categorized all samples “excellent” class for irrigation except 2 groundwater samples. 15 samples were “suitable”, 3 were “marginal” and 4 were “unsuitable” for irrigation in respect of RSC. For HT, 13 were “moderately hard” and 09 were “hard” limit for irrigation and samples were suitable for drinking and livestock consumption. Asian J. Med. Biol. Res. March 2020, 6(1): 44-55

The role of mural mechanics on cephalopod palaeoecology

Cephalopods transformed the molluscan shell into a buoyancy device that must be strong enough to resist external water pressure. Historically, unique features of the shell have been interpreted on the basis that the strength of the shell presents a hard limit on maximum habitat depth. One such feature is the mural flap, which is a semi-prismatic layer deposited on the inner surface of some coleoid septa that has been suggested to strengthen the shell and permit colonization of deeper waters. We test this hypothesis by constructing finite-element models that show how mural modifications affect the response of the shell to hydrostatic pressure. The mural flaps are found to have no notable structural function. Another mural modification discovered here is the adapical ridge flap that initially seemed to have a potential function in shifting peak stress away from the attachment site of the septum; however, the irregular distribution of this feature casts any functional interpretation in doubt. Ecological separation of belemnites and decabrachians is likely not mediated by the presence/absence of mural flaps. This work illustrates a potential caveat that not all unique septal features formed in response to increasing hydrostatic pressure and deeper habitats.

“Innovation” Discourse and the Neoliberal University: Top Ten Reasons to Abolish Disruptive Innovation

Innovation is a core neoliberal economic strategy, and the research university is a privileged site for its incubation and practice. Most senior university officials believe that the university’s stature, funding, and fate depend on maintaining its reputation as a primary innovation source and look to purge elements that do not appear to fit that purpose. This chapter argues that this neoliberal policy agenda is, in effect, fighting the latest and possibly the last economic war. The chapter begins with a brief intellectual history of innovation as a business concept, focusing on the development and influence of Clayton Christensen’s innovation theory. It then offers a critical analysis of the role of innovation in the contemporary global research university. In turn, it presents the argument of Giovanni Arrighi and others that the “Western development pathway” has reached a hard limit. Finally, the chapter posits that the sustainable, post-neoliberal economy-to-come will depart from the current pathway by replacing energy-intensive technology with skilled and educated labor.