Biology subjects

Naim, M.

Publications and source records attributed to Naim, M..

7 recordsLinked to original sources

bioRxiv2026

Planting set-up and local environmental conditions affect outcomes in tropical agricultural restoration

1. Fine-scale environmental metrics, including spatial configuration and identity of surrounding plants, can strongly influence plant survival and ecosystem functioning. However, tropical restoration projects rarely test their role. Within the Riparian Ecosystem Restoration in Tropical Agriculture (RERTA) Project, located within oil palm plantations in Indonesia, we investigated how the spatial configuration and position of enrichment-planted trees influenced restoration outcomes within actively restored riparian margins. 2. We compared the enrichment plantings' response to fine-scale spatial conditions, either planted with conspecific (same-species) or heterospecific (mixed-species) neighbours for six planted tree species (Peronema canescens, Shorea leprosula, Alstonia scholaris, Artocarpus integer, Calophyllum inophyllum, and Albizia chinensis), in restoration areas with mature oil palms either left in place (shaded) or removed (unshaded). We also tested whether restoration outcomes varied with position within the margin (river, middle, or edge). We measured plantings response as seedling survival and height (monitored over eight years) for all six species of trees. 3. We also carried out more detailed observation on multiple ecosystem functions associated with focal trees of three of the species (Peronema canescens, Alstonia scholaris, and Albizia chinensis), measuring differences by planting configuration and distance to river edge. Functions measured included: herbivore predation, leaf herbivory, litterfall, soil chemical properties (organic carbon, cation exchange capacity, total nitrogen, and phosphorus), and soil physical properties (bulk density, aggregate stability, friable soil content, and A-horizon depth). 4. Survival and height did not differ between conspecific and heterospecific neighbours, but did with position within the riparian margin, but only when analysed by treatment and time. Planting configuration and position influenced ecosystem functions; heterospecific plantings had greater soil aggregate stability and higher ant densities, while increasing distance from the river was associated with lower arthropod abundance and herbivory but greater predation. 5. Our findings demonstrate that planting outcomes are strongly context-dependent, with local seedling configurations, position within the riparian margin, and restoration treatment interacting to influence restoration success and local ecological conditions. Our findings provide experimental results to inform planting strategies and restoration protocols in agricultural landscapes.

ecology↗

bioRxiv2026

From margins to mainstream: restoration of riparian margins to support oil palm sustainability in modern and future climates

Palm oil is the worlds leading vegetable oil, with production continuing to expand, particularly across Southeast Asia. Within established plantations, conserving and restoring riparian margins can reduce erosion, improve connectivity, and support biodiversity. Simultaneously, climate change is increasing thermal stress within tropical agricultural landscapes, raising the potential importance of riparian buffers as microclimatic refugia, although this has not previously been evaluated. The Riparian Ecosystem Restoration in Tropical Agriculture (RERTA) Project is a long-term Before-After Control-Impact experiment established within oil palm plantations in Riau, Indonesia, to evaluate alternative riparian restoration strategies following plantation replanting. Treatments included passive restoration (retaining mature oil palms and allowing natural regeneration), active restoration (enrichment planting with six native tree species), and a control (replanting immature oil palms to the river edge). Six years after restoration, we assessed vegetation structure using terrestrial laser scanning and thermal stability using temperature loggers and thermal imaging. We also evaluated the long-term temperature buffering capacity of each treatment under current and projected climates using CHELSA climate data and downscaled outputs from multiple General Circulation Models under Shared Socioeconomic Pathway scenarios for 2045 and 2085. Active restoration produced greater structural complexity, a more closed canopy, and cooler, more thermally stable conditions than passive restoration and control treatments. Restored margins also contained significantly more cool surface microhabitats, reducing thermal extremes under both current and future climate scenarios. Our findings demonstrate that active restoration of riparian margins can enhance thermal buffering and create microclimatic refugia for biodiversity within tropical oil palm landscapes. As agricultural intensification and climate change continue to reshape tropical ecosystems, restoring structurally complex riparian vegetation will be critical for sustaining biodiversity and the ecosystem services upon which agricultural production depends.

ecology↗

bioRxiv2024

Functional Dichotomy of Orbitofrontal Cortex and Anterior Cingulate Cortex Subregions in Decision-Making and Brain-Body Regulation

Mood disorders are associated with complex disruptions in brain networks, including those associated with the orbitofrontal cortex (OFC) and pregenual anterior cingulate cortex (pACC). The functional contribution of the caudal OFC (cOFC) has remained largely unexplored. We investigated the functions of the cOFC and pACC in macaques performing an approach-avoidance task by the combination of multimodal recordings and electrical microstimulation (EMS) of the cOFC. We assessed neural, autonomic and behavioral responses. We found the cOFC to be sensitive to both positive and negative stimuli, whereas the pACC was singificantly more active during aversive outcomes. EMS of the cOFC increased avoidance behavior, suggesting a causal role for the OFC subdivision in cost-benefit decision-making. Physiological measurements were positively correlated with behavioral patterns, emphasizing body-brain synchronization during emotionally significant decision-making. We suggest that the cOFC contributes to inducing pessimistic states, thereby making its dysfunction a potential contributor to the etiology of mood disorders.

neuroscience↗

bioRxiv2024

A morphing map model for place field organization in large environments

Navigation and spatial memory, essential for animal survival, are founded on the hippocampal formations ability to host spatial neurons marking an animals position. Within controlled settings, the place cells of the hippocampus are activated in specific regions, the place fields. In this paper, we introduce a "morphing map algorithm" based on bat data from a 200-meter tunnel, highlighting a multifield, multiscale spatial representation of place fields. This algorithm posits that in vast environments, bats opt to select landmarks or anchors for spatial representation. The method introduces a hyperbolic geometry in spatial representation, aligning with bat data from vast areas. We apply Procrustes distance to evaluate similarities between neural maps of bats and model-generated maps, revealing shared structure across bat maps, which might be dictated by common anchor points. Further explorations into anchor point ablation provide insights into their crucial role in map stability. The results present an evolved neural navigation strategy in expansive habitats and guide future spatial representation research across species.

neuroscience↗

bioRxiv2020

Effects of order on episodic memory of event times

Memorizing time of an event may employ two processes (i) encoding of the absolute time of events within an episode, (ii) encoding of its relative order. Here we study interaction between these two processes. We performed experiments in which one or several items were presented, after which participants were asked to report the time of occurrence of items. When a single item was presented, the distribution of reported times was quite wide. When two or three items were presented, the relative order among them strongly affected the reported time of each of them. Bayesian theory that takes into account the memory for the events order is compatible with the experimental data, in particular in terms of the effect of order on absolute time reports. Our results suggest that people do not deduce order from memorized time, instead peoples memory for absolute time of events relies critically on memorized order of the events.

neuroscience↗

bioRxiv2019

Emergence of hierarchical organization in memory for random material

Structured information is easier to remember and recall than random one. In real life, information exhibits multi-level hierarchical organization, such as clauses, sentences, episodes and narratives in language. Here we show that multi-level grouping emerges even when participants perform memory recall experiments with random sets of words. To quantitatively probe brain mechanisms involved in memory structuring, we consider an experimental protocol where participants perform final free recall (FFR) of several random lists of words each of which was first presented and recalled individually. We observe a hierarchy of grouping organizations of FFR, most notably many participants sequentially recalled relatively long chunks of words from each list before recalling words from another list. More-over, participants who exhibited strongest organization during FFR achieved highest levels of performance. Based on these results, we develop a hierarchical model of memory recall that is broadly compatible with our findings. Our study shows how highly controlled memory experiments with random and meaningless material, when combined with simple models, can be used to quantitatively probe the way meaningful information can efficiently be organized and processed in the brain, so to be easily retrieved. Significance StatementInformation that people communicate to each other is highly structured. For example, a story contains meaningful elements of various degrees of complexity (clauses, sentences, episodes etc). Recalling a story, we are chiefly concerned with these meaningful elements and not its exact wording. Here we show that people introduce structure even when recalling random lists of words, by grouping the words into chunks of various sizes. Doing so improves their performance. The so formed chunks closely correspond in size to story elements described above. This suggests that our memory is trained to create a structure that resembles the one it typically deals with in real life, and that using random material like word lists can be used to quantitatively probe these memory mechanisms.

neuroscience↗

bioRxiv2019

Fundamental Law of Memory Recall

Free recall of random lists of words is a standard paradigm used to probe human memory. We proposed an associative search process that can be reduced to a deterministic walk on random graphs defined by the structure of memory representations. The corresponding graph model is different from the ones considered in the past but still can be solved analytically, resulting in a novel parameter-free prediction for the average number of memory items recalled (RC) out of M items in memory: [Formula]. This prediction was verified with a specially designed experimental protocol combining large-scale crowd-sourced free recall and recognition experiments with randomly assembled lists of words or common facts. Our theoretical and experimental results indicate that memory recall operates according to a stereotyped search process common to all people.

neuroscience↗