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10. Risks and mitigations

Risk Mitigation
Transcript level ≠ functional channel density Use expression as a prior only, with wide variance; regulation sets the actual density
Transcriptome false negatives exclude real channels Channel presence is a spike-and-slab prior with detection-based inclusion probabilities; hard exclusion needs reporter or electrophysiological evidence (L2); truncation checked with π_min = 0 on the worm
Many invertebrate channel/receptor genes lack measured kinetics Homology priors + inference; flag sensitive unknowns for targeted electrophysiology
Per-type regulatory programs Φ are not identifiable from realistic data (fewer parameters, but still sloppy in the directions that matter) M3 identifiability gate runs before M4. If Φ fails to identify, change what is fitted (e.g. share regulatory gains across families of types, or fit set points only) or add the experiments the gate says are missing
Regulation rule misspecified (the mechanistic rule form is wrong even if H* is right) Fit a learned local rule family alongside the mechanistic one (L7); H* is judged on locality, not on one functional form
H* and R1 (genetic hardwiring) can't be separated with acute data Commission chronic-manipulation and timed-depletion datasets (roadmap); F3, F7a
Falsification tests are underpowered, so a negative result is uninterpretable Power computed by simulation at M3 on the real design; data requests quote required sizes; underpowered tests can only be inconclusive (02-hypotheses.md)
A lost prediction contest is over-read as biological evidence Decision rule separates predictive selection from mechanistic evidence; negative mechanistic claims require excluding missing mechanisms, weak interventions, insufficient measurement and optimization failure
Commissioned datasets arrive late or not at all Tracks A–C produce results from public data first; the decision rule names which verdicts are possible without F3/F7 (R2 vs. rest)
Platform-first trap: years of infrastructure before any science Adopt existing tools first; extract platform components from working code (07-platform)
Connectome-free data-driven models match CAKE, so anatomy and physics add nothing measurable Baselines are scored from M0; CAKE's claimed advantage is generalization to unseen perturbations (E5), which is tested explicitly. A tie there is a publishable negative result about the value of mechanism
Leakage between priors and validation data inflates results Leakage audit at M0 and on every benchmark release
Regulation machinery can't reproduce even a known case, making H* tests uninformative AFD positive control must pass before M4 tests H*
Fixed synapses can't reproduce learned behavior Associative plasticity in L7 for well-characterized circuits; E4 includes learned behavior
Results depend on an assumed rearing environment Default to the data-generating lab conditions; report sensitivity to alternative rearing distributions (L7)
H* is false (regulation does not determine θ well) F1–F7 are run to outcomes in P0. If H* is rejected, fall back to per-type direct fitting with the same infrastructure. If it stays undecided, P1 proceeds with the predictive selection. The Necessity Map and H2/H3 still stand
Chaotic dynamics break gradients Multiple shooting, teacher forcing, shadowing gradients for time averages, compare statistics rather than trajectories for E3
Too many positive Lyapunov exponents make shadowing gradients expensive Measure the Lyapunov spectrum on the worm in M2; fall back to ensemble likelihood-ratio estimators or shorter statistic windows
Fixed-point burn-in misses slow regulation dynamics (e.g. hysteresis, multiple fixed points) The developmental outcome is defined by the dynamics, with an explicit selection rule (L7); endpoint mode only under validity conditions V1–V8 and with certification (residual, stability, basin check); otherwise transient mode; validated against direct burn-in on the worm
Root-finder converges to an unstable or unreached equilibrium Stability check on the loop gain and basin check against transient integration from the initial state (06-compute.md §5.2); pseudo-transient continuation follows the flow
Warm starts or cache hits select a different branch Warm starts only with certification; cache keys include initial-state and schedule samples (06-compute.md §8)
Constant-gain mechanistic rules cannot produce lasting developmental history effects (F7b) Known in advance (L7); the learned family includes state-dependent and higher-order rules; F7b estimates which mechanism carries history rather than assuming one
Regulation rates unidentifiable from equilibrium data Known gauge (L7); rates fitted only from transient data (F3/F7 time courses), which the commissioned datasets provide
Regulation-level waveform relaxation fails to converge (strong regulation–network feedback) Estimate the spectral radius of the outer iteration during the run and switch to the joint solver above 0.9 (06-compute.md §5.3); measure how often this happens on the worm
Reduced model drifts out of its validated regime N1 reductions certified over a declared parameter domain, rebuilt on exit; fidelity probes with automatic refinement (06-compute.md §3, §9)
Local reduction error underestimates error in network or behavioral results Goal-oriented (adjoint-weighted) error propagation and coupled paired-replica comparisons with feedback on, including closed-loop behavior (06-compute.md §9)
Lumped synapses misrepresent stochastic release or receptor saturation Lumping exact only under stated conditions; otherwise a validated approximation (S0/S1) with distributional CI tests against per-site models (06-compute.md §3)
Results differ across hardware or batching despite identical RNG streams Bitwise reproducibility only within a reproducibility class; statistical equivalence across classes, tested in CI (06-compute.md §4.6)
Benchmark metrics accept predictions with wrong amplitude or timing Primary losses score amplitude and timing (trace MSE, effect-size and trajectory losses); correlation only as a diagnostic (03-evaluation.md)
H3 residuals attributed to latent edges when they come from other model errors Structured decomposition with competing error sources, coherence diagnostics, and a synthetic specificity check before F6 (02-hypotheses.md)
H2 headroom mistaken for validated prediction B1 reports headroom only; F5 needs a named dataset with sufficient bandwidth, transmission-mode labels and an observation model
Brain states are not Markovian at a usable lag time, so stratified averaging is biased Implied-timescale tests; fall back to longer time-averaging windows (higher cost)
Content-addressed cache serves stale results after a silent code change Cache keys include code version, reproducibility class and full input hashes; periodic random re-computation audits
Spec documents drift out of sync with each other or with the code Each document has an owning working group; cross-document links checked in CI; decisions recorded in the decision log
EM morphology errors (diameters, shrinkage) Treat as latent with priors; test sensitivity
Individual variability vs. single-reference connectome Use multiple connectomes where available (worm developmental series, fly female/male/BANC); report predictions as distributions
Developmental connectome series mixes age with individual variation Probabilistic developmental wiring model (age trend + individual deviation); burn-in on sampled histories; report branch-switching fraction (L7)
Compute estimates prove optimistic All budget numbers are feasibility hypotheses with a testing milestone and a re-plan criterion; end-to-end workload benchmarks (06-compute.md §10)
Information-budget tolerances are too loose because local Fisher estimates miss nonlocal errors (branch switches, bifurcations) Coupled comparisons measure the total Δ on validation runs and calibrate local estimates; certification checks 2–3 are never relaxed by Fisher weighting (12-information-budget.md §4.3, §8)
Budgets certified on one benchmark version silently fail on a larger one Cached artifacts record their Δ and benchmark version; configurations are re-certified per version (12-information-budget.md §1)
Imaging cannot supply information as fast as chaotic dynamics create it, so trajectory fitting is ill posed Data-rate gate before fitting; failing tasks are scored as distributions (12-information-budget.md §6)
Low-precision early solver iterations switch equilibrium branches Precision schedule in the solver's own metric, kept below the stability margin; basin check unchanged (12-information-budget.md §4.3)
Milestones depend on components scheduled later Minimal regulation simulator and reduced closed loop (M2b) precede M3 and M4; A0 demonstrator precedes both (09-roadmap.md)
Compute cost Reference fidelity only for small systems and validation; reduced models gated by the Necessity Map
Data access and licensing Ingest only open datasets first; record licenses in provenance metadata